If you buy a used car, it is really important for you to know how to fix it. Most of the work you can do yourself and will need simple tools to do the repairs. You can find almost anything you need to know, on youtube videos. If you do buy a used car, and breakdown or start noticing problems, you will save a ton of money by doing the repairs yourself, they are a lot easier than one would think. Say something simple, like a water pump costing you $30 in parts and three hours of work, that could shoot up to hundreds of dollars at a garage.
You really don't need experience, you don't need to be a mechanic to do most of the repairs, it just requires a little patience, the right tools (mine are cheapo Walmart ones), and a guide such as youtube. Specialty tools are almost always available cheaply to rent, at auto part shops, so you don't need to buy those. Once the engine, computer or transmission go, I would say just get another car, unless you get really good at repairs. Everything else though, you should be able to repair fairly easily.
If you rely on a garage to do the repairs, it gets really expensive when things start breaking down, which is almost always inevitable with used cars with 150k + miles. Plus you never know how the previous person drove the car you are buying, they could have beat it to a pulp, then there are just lemons that have one problem after another, right out of the dealership.
Before buying a used car, be sure to do a lot of research online as for what to look out for, how to do a proper inspection, this will help you in the long run.
If you buy a new car, get one that has a good warranty that will last as long as your payments.