I started doing my own biogel/gel-x nails in highschool. It's more accessible than people think. Here's the list of all the products you need to start that I wish I had back then.
You're going to need a UV lamp to cure your gel polish or biogel. Been using it forever, no complaints.
Modelones UV nail lamp
If you're doing biogel, you need this to smooth out the surface and shape. There are cheaper options available on Amazon.
Nail drills
For prep, remember to buff your nails before adding any extensions and push your cuticles back.
Nail File/Buffer, Cuticle Cutter/Pusher
You can use these tips or buy press-on ones for nails.
Pre-Shaped Nail Tip Extensions
Works. I did gel-x nails on a client using these to glue press-on tips, and they lasted her a month.
5 pcs KDS Nail Tip Glue
For biogel, sculpting, and design.
Biogel Brushes
Use before biogel to ensure adhesive longevity. Cure for 60s under lamp.
IBD LED & UV Bonder
This is the biogel I'm talking about. The product they use in the nail salons here. IBD has different colors too, so if you do french tips a lot you can buy the pink base.
IBD Builder Gel
After you've drill-filed the biogel and you're ready to start painting, base coat layer first before your nail polish, and top coat last to finish everything off.
Beetles Gel Base and Top Coat
Need this to wipe down nails after biogel so you can drill-file.
Isopropyl Rubbing Alcohol
For Cateye nails, you need a magnet to control the sparkle.
Nail Magnet
Add after a no-wipe top coat layer.
Chrome Powder
For all things design.
Nail Design Brushes
A good place to start for affordable UV gel polish colours. I personally love buying korean brand ones, but these are great.