This Unity tutorial shows how you can spawn enemies in your project. I show three examples: how to spawn enemies in general, how to make a monster spawner like in Minecraft, and how to spawn enemy waves. I include the scripts in the description below as well, cheers!
Scripts
Monster Spawner: https://pastecode.io/s/fpb0sz26
Single Spawner: https://pastecode.io/s/q2tme70a
Wave Spawner: https://pastecode.io/s/fq6tf4v3
Player: https://pastecode.io/s/tt0jkw8u
Enemy: https://pastecode.io/s/c8ku6ym5