hello, I think i can help you.
There are different ways. to start, you may want to download a program, if you need one for free, Krita is a good one, but if you are willing to pay, Clip studio paint is a great option.
when you get to draw, you can do some of the following
-you can try and use your mouse, this is way harder, but not impossible.
-get a drawing tablet. There are different types and prices, some of them have no screen, but are an excellent way to start and are way cheaper. The ones with screen are kinda expensive, but are more professional.
You can also use your phone or a tablet/iPad.
in this case, Clip studio, Sketchbook or Ibis paint are great options, but if you have an apple device, you will be able to use the previously mentioned programs, and some others, Procreate is an amazing example, tho you have to play for this one.
I hope this helps! :D