Welcome to the forum!
Regarding advice, the best advice anyone can give you is to take some time and figure out how to use the
Advanced Thread Search tool here.
There are over 20 years of archived discussions here. Over 500,000 threads covering literally everything you could ever want to know about owning, operating, repairing, and maintaining arcade games. Just about any question you could have (or any problem you can have with a specific game) has been asked, answered, and discussed, usually multiple times. The collective knowledge of what's in the archives here is vastly superior to what any one current member here will know. So we encourage folks to always take some time to search for your questions first, before asking the forum.
You can literally spend years just reading the archives here (I did), and learn as much as you want to know. The only trick is finding the right stuff to read, and the search tool is the key to uncovering all the gold buried in the archives.
Since the search does not work the same way as Google, there are some tricks to using it. There's a post with some details and examples
here.
Every game has many common pieces of knowledge that are specific to that game, and/or games similar to it. So I'd recommend starting by just searching for threads with 'Tron' or 'Space Invaders' in the thread title. Also 'Tron problem', 'Tron issue', etc. Then expand your searches to include post bodies as well.
You'll know you've read enough when you start seeing the same information over and over. But every game has common problems, common solutions, and other 'tribal knowledge' about replacement parts, troubleshooting, etc. Learn as much as you can about one or two games, and then when it's time to expand to others, it'll get easier.
Also, if you don't already have one, get yourself a digital multimeter (DMM). I recommend the UNI-T model UT58D or UT58E as a decent quality 'cheap' meter, you can get them on Amazon or Ebay. You don't need to spend a lot, it'll cost you about 60 bucks or so. But knowing how to use a DMM is a critical skill for this hobby (and your own safety).
Welcome to the forum and hobby.