Need some help with locks and doors

I wanted to see if anyone on this forum could point me in the right direction. My drivers side door handle no longer springs up and down. I have to actually lock in while I am driving or it will swing wide open on a turn. Is there a part I can buy to help fix this and if so, do you guys know of a good tutorial or instructions that can show me how to do it?



Also the lock on one of the doors is not working properly, any guidance on how to repair or fix the locks in these doors would be very much appreciate.



Thanks in advance.