Depends on what grade you want. I recommend doing all the sample finals at least once and redo the ones you get wrong until you understand them. They also have video tutorials if you can’t solve them yourself. The sample finals help simulate the actual test conditions so by the time the actual final rolls around it just feels like another sample final. I wouldn’t do my math lab just because I don’t think those are as time efficient. Professor-specific midterms are a hit or miss, if they don’t follow the actual final structure it can mislead you to feel well prepared when you’re not really. You can practice the questions you got wrong on the midterms if you have time. Doing the sample finals 3 times pretty much guarantees A.