Know where to go for parts
Fixing your car yourself is a decision largely based on money. So, you should be looking to save in every aspect possible. Brand-new parts are not necessarily a necessity. One of the smartest things is to go to a pull-your-own parts junkyard like U Pull & Pay or a similar place. Here, you'll find parts in used but usable condition at a much better price than you would find brand-new.
Since you're a novice in the world of automotive repair, you should be absolutely receptive to the wisdom of others. Talk to friends and family members who have repaired their vehicles themselves. They might get your advice that you hadn't considered, but is absolutely crucial.
Do your research
Repairing a vehicle isn't like cooking. You shouldn't try to experiment with different flavors. You need to follow protocol and not cut any corners. Before making repairs, look for resources online about your car's problem(s). It doesn't need to be a dry/boring process either. Find mechanics with videos on YouTube that interest and educate you, and you'll be able to learn in a much more enjoyable way.
Safety is an absolute must when it comes to automotive repair. If you find yourself dealing with all the machinery under your hood, you should not take any chances. Look into proper clothing and pay attention to your environment. Make sure you aren't smoking around your car while fixing it and be mindful of any chemicals you might be using. It's no good fixing your car if you damage your body in the process.
Don't bite off more than you can chew
You might want to feel impressive and accomplished by transforming a clunker into a sleek speed machine on your first go, but that's not terribly likely to happen. You need to build up these skills, rather than trying to get to the top right away. Even the best mechanics had to start small with things like basic framework repair or learning how to perfectly change a tire. Don't get ahead of yourself and work at the best pace possible.
The feeling of accomplishment you'll get from fixing your vehicle is immense, even if it's a seemingly minute remedy. Make sure to take all the necessary precautions for safety, get the right parts at the right price, and do your research. If you do, you'll be able to save money and feel great in the process.