How to be good at Minecraft on a Mac?

I'm not trying to act spoiled because it wasn't even me who wanted this computer. But I just literally hate my computer. It's not designed for Minecraft really.
1st: You can't click the mouse fast enough, so you always die in pvp

2nd: There's no Right click, so your stuck holding Control and clicking for a right click (Which sucks)

3rd: It's always hard to figure out everything on the controls, so everytime you hit the wrong button, The mac goes crazy, and you can't concentrate.

I mean I love this computer for school, and work but seriously. If you were to recommend a cheap gaming computer, what would you say? And if not how to fix everything and click faster?

It sounds like everything could be fixed by just getting a new mouse. I think you're hitting keyboard shortcuts because you're pressing control with other keys. I've never used a modern day Mac but I'm pretty sure they can use any standard USB mouse if you have one lying around your house.