dear aap:
I want to make music, but I don't want to be in a band. I think it would be cooler to make songs and music for videogames. How do I do that? Where do I start? - unsigned.
Dear Unsigned-
Ahh, the future. There was a time when every kid wanted to be a baseball player. Then every kid wanted to be a rock star. Some kids wanted to write the ultimate novel. Other kids wanted to make movies... now everyone under the age of 15 that I talk to wants to make videogames. I'm not saying that as an old fossil, I'm just pointing out the truth of it. Desires and thoughts of what is "awesome" shift with the generations, that is the way of the culture and that is cool, but one thing is constant: a tiny percentage of the kids who wanted those dream occupations ever take the steps necessary to make their dreams (possibly) come true... and only a tiny percentage of those people actually get that ultimate gig/life.
I'm not saying this to discourage you. I'm saying it to double-down your determination.
I know that video games buy/commission some real "songs" from established recording artists for specific games, but from the sound of it you were talking about making the 'music' for games too, and by that I assume you mean the scores/background music that fills gameplay and cut scenes. Before you even get to thinking about how to get specifically into games you're going to need some basic skills... and then some advanced skills... and hopefully some innate talent... and then some pure luck. But you asked "Where do I start?" so I'll tell you.
1) Piano Lessons.
Yes, and maybe years and years of them. You said you specifically don't want to be in a band... so buying a guitar and taking four quick lessons from the local stoner isn't going to give you the foundation you'll need. That foundation can be found in the piano, and in real, structured study of music theory. You'll need to be able to read music too, and understand rhythm and harmony and melody and all those words that serious musicians bandy about so easily. Seriously. Think of it like learning a foreign language- of the country you plan on moving to. "Real" musicians start at the piano. It is the most straight-forward instrument on which to learn the basics of all the things I just mentioned. Once you have the basics really down pat, then you'll branch out into learning all the styles of piano and keyboard music. Then you'll branch out into orchestration and all sorts of music theory. These are the basic building blocks.
2) Immerse yourself in gaming and gaming culture.
By this I don't mean just PLAY videogames every waking moment you're not seated at the piano (although, of course I assume you're an avid gamer already.) I'm saying you'll need to get into the esoterica and behind-the-scenes stuff. Start reading gaming INDUSTRY blogs and websites. Basically I'm saying: After you know the 'language' of your new foreign country home you have to also know the history and culture.
3) Start making stuff.
Start making your own games (another thing to learn) and/or align yourself with people who have a passion for making games so that you can learn about HOW games are constructed and how the music fits into the overall structure... maybe throw some understanding of coding and computer science into your bag of tricks. You'll also hopefully gain some experience in actually creating music for them. DIY still applies to the world of videogame-making... more NOW than ever.
So that is the most basic starting path. Develop the basic skills now, so that the advanced skills won't be as much of a reach for you later. Don't give up and don't get lazy, if this is what you want.
Good luck.