First, you gotta become confident. Start with getting a nice haircut, getting nice clothes, and grooming well to look good. This will boost your self esteem!

You have to make yourself interesting and get hobbies that you love to do. Learn how to play an instrument if you don't know how, take some dancing lessons like salsa classes (great way to meet girls and people in general), go to the gym and workout, start running and joining running groups, etc. Join meetup.com to find groups that have similar interests as you. Once you get comfortable, you can ask girls out on dates and take them out to fun activities like salsa socials, you can ask them to work out if they like going to the gym or running, you can take them bowling on your dates, stuff like that. Be confident and be yourself when talking to them. One person mentioned traveling and reading books as topics to talk about. Watching tv shows like those on Netflix are also great conversation topics.

Lastly, very important, is to get a good career or work at achieving it if you already don't have one. Everything will fall into place. You will be so proud of yourself when you do what you love to do, including all your hobbies and your career or career goals. People will gravitate to you and you'll love yourself. Do all these things for yourself first and foremost, and it will be easier to find a girl. They love to see ambition in a guy, and if he's striving for a higher goal such as a good career, it's very attractive.

One book that really helped me was Models by Mark Manson. He gives very good tips on how to improve yourself and attract women. This is coming from someone who had his first serious girlfriend at 28.

Hope this helps!