working code but i need a serial plot

I have got a working Arduino EMG code here

// Grove - EMG Sensor demo code
// This demo will need a Grove - Led Bar to show the motion 
// Grove - EMG Sensor connect to A0
// Grove - LED Bar connect to D8, D9
// note: it'll take about serval seconds to detect static analog value
// when you should hold your muscle static. You will see led bar from level 10 turn to 
// level 0, it means static analog value get ok

#include <Grove_LED_Bar.h>

Grove_LED_Bar bar(9, 8, 0); 

int max_analog_dta      = 300;              // max analog data
int min_analog_dta      = 100;              // min analog data
int static_analog_dta   = 0;                // static analog data


// get analog value
int getAnalog(int pin)
{
    long sum = 0;
    
    for(int i=0; i<32; i++)
    {
        sum += analogRead(pin);
    }
    
    int dta = sum>>5;
    
    max_analog_dta = dta>max_analog_dta ? dta : max_analog_dta;         // if max data
    min_analog_dta = min_analog_dta>dta ? dta : min_analog_dta;         // if min data
    
    return sum>>5;
}

void setup()
{
    Serial.begin(115200);
    
    long sum = 0;

    for(int i=0; i<=10; i++)
    {
        for(int j=0; j<100; j++)
        {
            sum += getAnalog(A0);
            delay(1);
        }
        
        bar.setLevel(10-i);
    }
    
    sum /= 1100;
    
    static_analog_dta = sum;

    Serial.print("static_analog_dta = ");
    Serial.println(static_analog_dta);
}

int level       = 5;
int level_buf   = 5;

void loop()
{

    int val = getAnalog(A0);                    // get Analog value
    
    int level2;
    
    if(val>static_analog_dta)                   // larger than static_analog_dta
    {
        level2 = 5 + map(val, static_analog_dta, max_analog_dta, 0, 5);
    }
    else 
    {
        level2 = 5 - map(val, min_analog_dta, static_analog_dta, 0, 5);
    }
    
    // to smooth the change of led bar
    if(level2 > level)
    {
        level++;
    }
    else if(level2 < level)
    {
        level--;
    }

    if(level != level_buf)
    {
        level_buf = level;
        bar.setLevel(level);
    }
    
    delay(10);
}

However, I don't get anything appearing in my serial monitor and serial plotter and need it to be if I want to get numerical results as well as the LED. I would like to know how that can be done

If you don't see the output from setup(), check the baud rate of the Serial Monitor. If you want to see more, add the required output code to loop().

You'll have to decide whether you want to see text in the Serial Monitor, or curves in Serial Plotter. Eventually add a button to indicate the desired output format, so that you can switch between both displays.

    for(int i=0; i<=10; i++)
    {
        for(int j=0; j<100; j++)
        {
            sum += getAnalog(A0);

How long did you wait for results?

I waited for a few seconds but got either only one result, or a non-integer. I would like to get a change of integers depending on the motion of my respiration, corresponding to the number of bars which light up.

I have got a working Arduino EMG code here

However, I don't get anything appearing in my serial monitor

That would be a strange definition of working, then.

but got either only one result, or a non-integer.

Since you can't be bothered printing in loop(), you can't expect more than one value. Since you print only one int, I can't imagine how you got a non-integer (value?).

Feel free to provide (lots) more details.

// Grove - EMG Sensor demo code
// This demo will need a Grove - Led Bar to show the motion 
// Grove - EMG Sensor connect to A0
// Grove - LED Bar connect to D8, D9
// note: it'll take about serval seconds to detect static analog value
// when you should hold your muscle static. You will see led bar from level 10 turn to 
// level 0, it means static analog value get ok

#include <Grove_LED_Bar.h>

Grove_LED_Bar bar(9, 8, 0);// Clock pin, Data pin, Orientation

int max_analog_dta      = 300;              // max analog data
int min_analog_dta      = 100;              // min analog data
int static_analog_dta   = 0;                // static analog data


// get analog value
int getAnalog(int pin)
{
    long sum = 0;
    
    for(int i=0; i<32; i++)
    {
        sum += analogRead(pin);
    }
    
    int dta = sum>>5;
    
    max_analog_dta = dta>max_analog_dta ? dta : max_analog_dta;         // if max data
    min_analog_dta = min_analog_dta>dta ? dta : min_analog_dta;         // if min data
    
    return sum>>5;
}

void setup()
{
    Serial.begin(115200);
    
    long sum = 0;

    for(int i=0; i<=10; i++)
    {
        for(int j=0; j<100; j++)
        {
            sum += getAnalog(A0);
            delay(1);
        }
        
        bar.setLevel(10-i);
    }
    
    sum /= 1100;
    
    static_analog_dta = sum;
}

int level       = 5;
int level_buf   = 5;

void loop()
{

    int val = getAnalog(A0);                    // get Analog value
    
    int level2;
    
    if(val>static_analog_dta)                   // larger than static_analog_dta
    {
        level2 = 5 + map(val, static_analog_dta, max_analog_dta, 0, 5);
    }
    else 
    {
        level2 = 5 - map(val, min_analog_dta, static_analog_dta, 0, 5);
    }
    
    // to smooth the change of led bar
    if(level2 > level)
    {
        level++;
    }
    else if(level2 < level)
    {
        level--;
    }

    if(level != level_buf)
    {
        level_buf = level;
        bar.setLevel(level);
    }
      Serial.println("level");
    
    delay(10);
}

The code works because, when it is entered, the LED bar goes down to zero, and increases with an increase in electrical activity. However, when I turn on the serial monitor, it lists random symbols and scrolls sideways, rather than listing the integer result of say, level

I now have it working to some degree as I have numbered results, but these only arrive before I press serial monitor, and appear when I activate it, but the random symbols come afterwards.

However, when I turn on the serial monitor, it lists random symbols and scrolls sideways, rather than listing the integer result of say, level

You don't print the value of level. You print the string "level" which is NOT useful information. The rest of your problem statement sounds like the Serial Monitor (or whatever app you are using to see the serial data) is not set to use 115200 baud rate.

PaulS:
You don't print the value of level. You print the string "level" which is NOT useful information. The rest of your problem statement sounds like the Serial Monitor (or whatever app you are using to see the serial data) is not set to use 115200 baud rate.

solved the string problem by removing the " marks. I still don't know hot to adjust my serial but will try