Welcome to the forum. You started at the right place with free laser designs. The tips and tricks and matrix of tutorials has lots of design assistance.
Choose a design software and start using it. I use Inkscape. It’s free and there are loads of tutorials and lots of folks use it on the forum.
Watch YouTube videos. They can really help.
Best way is just to start simple and go from there. My first earrings were hardwood initials of the wearer. Easy enough skill to master. Throw some text down. Convert to paths. Do a union. Add a hole.
Make sure the font’s counters (cutouts in As and Os and Bs) don’t trip you up.
In no time you will be making earrings like these masterpieces form @cynd11!