This is fairly simple (for an Arduino project).
The "trick" if you are a beginner is to start with a simple program (like the Analog Read Serial Example) or a "program outline", and then add one or two lines of code at a time, test-compiling and test-running as you go. That's not quite as simple as it sounds because you can't just start at the top and work down... The compiler needs to see a "complete program".
The other trick with the Arduino is to use print statements and the Serial Monitor (like the Analog Read Serial Example) to show variables, or to show little messages about what the program is doing, etc., so you can "see" what it's doing as you are "developing" the program and/or if it's not behaving as expected.
Also, work on the input & output separately. I'd probably start with temperature measurement.
There are lots of temperature sensors that will work. The analog [u]LM35[/u] ("calibrated" in Centigrade) and LM34 ("calibrated" in Fahrenheit) are probably the easiest to use.
In software, you just need to [u]map()[/u] the raw analog-to-digital reading to temperature. (This will take a little math with ratios... The ADC is reading voltage, but not in units of "Volts". i.e. The reading is proportional to the voltage, so the actual voltage can be measured/calculated. The LM35 datasheet does give Volts, but you can go directly from the raw reading to temperature, or your software can convert to Volts first, if you find that easier or if it makes you "feel better".)
Then you need an [u]if-statement[/u] to turn-on the heat if the temperature is below target and off when it's above target. In the real world, it's common to use a little [u]hysteresis[/u] so it doesn't switch on & off too rapidly, but that's up to you.
temperature of the heating plate
What's powering the heating plate? A MOSFET driver circuit can be used with DC. If it's powered from 120 or 220VAC, [u]this "industrial" type of solid state relay[/u] can be controlled directly from the Arduino, and they are easy to wire-up and easy to mount. (A regular electro-mechanical relay needs a driver circuit, or you can get relay boards with a relay and driver built-in.)
If you wanted to add an LCD display and a temperature adjustment knob/switches, that can be done but your project gets more complicated.
My knowledge to programming and Arduino is close to none. So, I need help please.
How about electronics? Since this is apparently a student project, maybe you an find an electronics student to help. An electronics major (in college) should know enough programming to help with this.