I have no friends in high school or college. What should I do?

You should try to find new friends online, coffee shops, libraries, events at convention centers, or join volunteering organizations.

Maybe you should start initiating conversations and approaching people instead of waiting for them to approach you.

You don't need friends. Everybody leaves in the end, yo should be your friend, lover, and everything, all you ever need is you.

Depending if you have social anxiety or not, intervene into groups. Find people who are most like you. Alternatively, you could benefit or help people when they are open to. To summarize, find something to do with others will get you points. If you have social anxiety, try it on a smaller scale. Evaluate from the side lines and look for a chance to offer opinions on how you feel that you know they agree with. This takes the anxiety of rejection away.

I went through and I am going through the same thing right now, just focus on you, your goals and your dreams. It can be lonely at times, but we can make it through no matter what!

Well i always recommend people to be themselves, even if being yourself doesn't get you any friends, because if you pretend to be someone else on the long run you aren't going to feel any kin dof connection with the friends you got being that way, so yeah basically be yoursefl and probably someone will wan to be your friend sooner or later, and also is quite important to stay open and humble.

I spent time learning about my hobbies in depth. In time, that interest brought me in contact with people who had the same hobbies as I did.

you should try to go to more social event's or talk to someone and find out more about them and see if things work out :)

Getting involved in extracurricular activities is a great way to make new friends and connections.

Join a club, go to a local event, get a hobby and find people who also enjoy it. These are just a few ways in which you can build new relationships but it has to take action on your part in order to do it.