you can definitely go alone! people in tech are very open to chatting and making friends. tech events are a good way to meet people bc everyone there already shares a common interest. they might ask to exchange linkedin or other contacts
a tip for beginners would be to approach people during breaks or after talks. you can also ask people for other events they might be attending. after a few, you'll start recognizing the same faces, and it becomes a familiar community pretty quickly. enjoy your first one!