You can do face to face, but you'll move a lot slower that way. You can reach thousands - millions of people from around the world online, all at the same time, 24/7. It's much quicker.
If you do choose to go face to face, go face to face with larger crowds. Don't go face to face to people one by one. That's a huge waste of time and it will actually hurt your name. Singled out people have no interest in hearing your pitch, and if you bug them too many times, you'll lose their ears forever. They'll associate your name with annoying and will actually work against you. You definitely don't want somebody telling their friends that your name is bad, especially when you're starting out. People in a large group are much easier to persuade into following you because of the group think. If somebody sees that hundreds of people are crowded around you, they'll feel more comfortable joining the crowd and making it 101.
If you can't form a large crowd yet, that's okay. Like I said earlier, and even at this point, don't go to people one by one (just please don't get accustomed to doing this, period...). Try to leverage somebody else's crowd. See if they'll let you play before them to the crowd they've gathered. Or maybe they'll add your music and merch to their table, or give you a shout out during their show. This is much quicker. And this way, you'll get more eyes and ears exposed to your talent, all at the same time.
But ya, sure...face to face is good, and everyone should go to their local crowds, but be aware that it's almost year 2020. Don't be completely stuck in the 90s when your competition is looking and moving into the 2020s.
Having a online presence that can attract a lot of people from around the world, 24/7 (even while you sleep) is by far the most effective.
Hope that helps. Cheers.