Is it possible to have a fulfilling life without socializing much and can someone make friends in the future if they currently do not have many?

Of course. Whatever makes you comfortable and happy, is what matters. There's no set rules and we shouldn't feel guilty about simply doing what we want to do. If we decide we're tired of something or it didn't work out the way we wanted, then we can change things. That's a beauty of choice and being human.

Yes as long as you aren't too antisocial or weird or put you're hangups on others and do know how to socialize and realize life doesn't revolve around you like most people think today.