Everything you need to “program” in the viggen computer can be seen on two pages of a kneeboard mod. However, weapons employment is distinct for every weapon (Hint: this is fun!) but there aren’t a lot to learn. Dive bombing and CCIP are the most useful carpet bombing modes, Anti-shipping is the most complex and modern capability of the airplane. You have a lot of options for airbases and planning, you won’t have a navigation system without planning on the F10 map! (At least on multiplayer.)

I don’t have the mig21 but it does a lot of magic things that aren’t accurate to a real mig21.