For Godot users:
Bullet tutorials often use an Area2D for the bullet and simply move it by changing the position.
This works for most cases and should actually be fairly lightweight. However, it breaks down if your bullets are fast and your targets are small. You can calculate how fast you can make your bullets go this way by looking at the size of your area2D and the size of their target.
IF you want your bullets to go faster than the size of your area2D and targets allow, then you need to come up with more clever ways to detect if they hit something. Raycasts are a possibility but people at the Godot discord (#physics channel) probably can give better advice if you give them the correct information.