Bruh, I'm 30M and haven't had sex in 30 years (I am engaged to a woman though).

To answer your question:

1. Make sure you're not hindering your chances by doing (or not doing) things under your control. So for example, your height is not something you can control so don't spend any effort worrying about that - but your weight, personal hygene, general fitness level, clothing (quality, style, fit) and personality (how fun you are to talk to) are all things you can work on in your free time. Now, you could be overweight, filthy, unfit, ugly, wear a literal sack and have as much charm as a tub of yoghurt and still get a woman to sleep with you (look around, it's very common to see attractive women with unattractive guys and the other way around. If you are average, then by definition 50% of guys your age are less attractive than you so don't be too hard on yourself) - but all those things hurt your chances. So if you have the time and energy, work on making yourself the best version of yourself you can possibly manage. Ideally in a sustainable way - don't just spend 6 months dedicating every waking second to the gym, snag a girl who's into muscular guys, then revert to your default state of zero exercise, resulting in you getting dumped 6 months later because you lose all that muscle and she no longer finds you attractive. This is why you constantly hear of the importance of "being yourself" - you will then attract a mate who's attracted to the real you (the "you" that you can sustainably maintain with reasonable effort - not the enhanced you that's the result of a superhuman effort on your part that you can't possibly maintain long-term). Hope this makes sense.
2. Finding a mate is all about numbers. You must kiss a lot of frogs to find your princess. I sure did. Well, there wasn't much kissing, just a lot of bad dates. Make sure you're actively approaching girls and asking them out. At best you can accept a 10% success rate (that is, out of every 100 girls you swipe on tinder, 10 will match and 1 will end up in an actual date, give-or-take). So persevere and learn to take rejection gracefully and move on. The problem with quiet introverted people like you and me is that we rarely get ourselves in situations where we can ask out single ladies (and the older you get the less single ladies without baggage there are in our age group). Tinder worked for me, but you'll have to do whatever is common in your area.
3. (optional) Do not come off as desperate. Be cool. Your attitude should be one of abundance ("there are 10,000 girls my age in my city. If this one rejects me, there's the other 9,999"). Being desperate or clingy is a potent girl repellent. Always be respectful, ask them out politely (don't be afraid to show your attraction), wait for the answer, and if it's a "no" take it gracefully, thank her for her time, move on and don't take it to heart. Don't get pushy or upset. Don't shower a girl with gifts and one-sided affection expecting her to go out with you out of pity or obligation (this is something every movie seems to portray, but is one of the least effective ways to try and get a woman). And when you're talking to a new lady, ask her out relatively early on, because if you get too familiar with them they'll start to see you as a friend and there's no escaping the friend zone except in very, very rare circumstances (the only time I've seen it happen is in my friend group, after a decade of friendship a pair of people realize they're the only ones in the group who are still single so they try going out together)...

Hope this helps. Here's an article I found very useful when I was in the same situation as you. Unfortunately the website is no longer on the web (all the good websites seem to go that way), but here's an archived copy from my bookmarks: https://web.archive.org/web/20190814174231/http://thematinggrounds.com/new-start-here/

The most important part is Part 3 ("What are women attracted to?") - it teaches you how women judge your attractiveness. Hint: many of the things you learn from movies is actually the opposite to how attraction works in real life. Over-the-top surprise "romantic gestures" are actually downright creepy.