Single chip computer


I’m trying to build a single chip computer based on a ATMega 1284 CPU, I wanted to add a keyboard and a connection to a TV, I would like to use the arduino TV library and a way to add a keyboard to the system, can anyone help me with programming and hardware?
If it’s possible I would also like it to run BASIC (The only programming language I know).

Post Scriptum, I know nothing about C++ or C.

Thank you.