How do I type in the language I am learning if my keyboard doesn't have the same letters?
You could always add a keyboard to your computer, there are many different keyboards that are available and then it allows you to type another language.
I recommend using phonetic keyboard layouts. You don't need to learn a whole new keyboard like the one you're using but have most keys in logical places, e.g.: σ under s, δ under d, ρ under r, λ under l etc.
The phonetic layouts should be available in settings in some OS's. If you don't have it, you can download one. Do you use Linux/Windows/Mac?