I have just had the car MOT'd, and it came back with some advisories. One being the offside cv joint, and the other was light misting of oil on one shock absorber.

I can get both shocks replaced and cv joint done for around £350 which is for oem parts. Is it necessary to get both shocks done? How will I know if the issue gets worse? Bit short of cash at the moment, so really want to put off as long as possible.

Always recommended to do both sides 

as above best to get both shocks done but being light misting it can probably wait, just check it by seeing if it bounces back up and settles when you press down on the corner of the car.

 

the cv joint probably needs immediate attention before it gets worse.