IF your goal is to learn how things fit together, work and are adjusted you can learn all that without wasting money on new parts. Just get your tools out, and strip the parts. Then disassemble, clean, relube, reassemble, reattach and adjust. If it all works you will have learned a lot and not spent a dime. If it doesn't work you have some more learning ahead.

An upgrade should result in the bike doing something better. Your plan won't do that.