Monitor vital signs

Hello everyone, thank you for reading.
I want to make a project that monitor the vital signs ( Body temperature, Heart rate, Respiratory rate, Blood pressure ) using Arduino.
Would you know which exact sensors I should use?
And all the hardware needed also, I'm a beginner so a bit lost.

Excuse me a bit, but if you are a beginner, how would you know what to do with such sensors and how would you know if you were getting reasonable results?