The L3 looks pretty good I can also afford it at the moment right now.
I've also heard computers can produce hashrate would that be possible for me to do at school you think?
You can’t make any money with that way, that’s pretty much cpu mining and unless your school has some powerful AMD processors to mine Monero, it’s not worth the hassle. Plus you will get in trouble if you do this since you are not allowed to mine on school equipment.
This maybe would of worked back in 2010 with BTC right before the GPU miners were launched but cpu mining has hardly been profitable for anything. Usually a GPU miner is released right away and it just dies off.