What to look for when buying a car

I’m in the market for a used car. I’ve never bought one before, but my old man is a strictly new car buyer, so he’s not going to be much help. Is there any kind of rule regarding how old a car should (or can) be if you’re buying used? What about mileage? Is there a “sweet spot” where the deals tend to be really good on the mileage front? I guess I’m just looking for guidance on how to think about buying a used car when it comes to maximizing the value for my money, the lifespan of the car, and any potential maintenance costs. Thank you everyone!

What tips and tricks do you use to get cheaper gas? Where do you normally fill up your tank and what do you do to save the most money?

So I just took this rice purity test online for the first time and got a 75. I haven't seen any of my friends' scores yet, so I don't know if mine is good or bad compared to theirs. I just want to get down to the meaning of it and if these scores are really something I should be that concerned about.

How do you figure out exactly what you can (or should) spend on a car? My clunker is probably going to die soon and I’m about to go car shopping, but I don’t really trust the dealer to level with me when it comes to the financing. I’m not sure if I’m going to buy new or used, and I’ve never taken financing out so I’m not totally sure what I should budget? Anyone got any tips or guidance on how you figure this kind of stuff out? It’s sort of overwhelming. For context, I want to know how much car can I afford based on a salary of about 50k.

So with my cat, she doesn't do this a lot but sometimes when I let her rub against me, she randomly bites me.

I'm trying to buy a used car but don't really know where to start. I've been fortunate enough to have my last (and only) car passed down to me from a family member, so I've never had to go through this process before and I'm terrified of wasting money or getting taken advantage of! Like, where do you go to get a used car? It feels like a basic question, but I see a lot of cars available online through private sale or from a dealer/franchise or used car lot, and tbh I'm not sure what the difference is or if any of these is better than the others? What should I be on the lookout for when I check out cars? How do you begin the process of getting the car inspected, negotiating price, etc.? Any tips I should keep in mind? Thank you endlessly!