If you do not have knowledge about the electronics then consider buying a cheap etching machine instead.
Take a look on https://hackaday.com/ and search for laser engravers.
I have found following articles in few seconds:
Cheap laser engravers
And this one is about 2018 list of laser cutters/engravers: 15 Best Laser Cutters, Laser Engravers & AIO Machines of 2018. It lists machines around 100$
- Meterk Laser Engraver ($125)
- NEJE DK-8-KZ ($70)
- QIILU Mini Laser Engraver ($130)
- SuperCarver K2 ($160)
Laser could damage your eyes (imagine laser reflection or if the machine falls from table when it's working). Take a look on wikipedia.
The best option is to use acrylic cover in same color as your laser, so you can observe the etching process and the laser beam is always blocked. For example take a look on orange cover of Formlabs Form 2 3d printer (it uses laser for printing).
Another protection is to wear laser protection glasses. Again the glasses must have same color as your laser.
Using laser for cutting or engraving means to burn material away. You should have good ventilation in the room.
Buy a smoke detector if you use cheap electronics with higher power consumption.