Help me get with the times

Thirty years ago I got a bunch of piercings - 2 in my lower ear lobes, my helix and nose. I’ve never changed my nose stud, and for the last 10-15 years I’ve only worn earrings in my lowest lobe holes. I’m hoping to start wearing jewelry in my upper lobe and helix piercings, but it seems the world has moved on without me. 🤣

I’m struggling to find simple, small solid gold (preferably 14k) studs or small rings in the big jewelry stores where I live, and google brings up all sorts of vendors I’ve never heard of. I don’t know whether the online shops are reputable or whether what they sell is legit gold.

I’m intrigued about flat back studs for my helix (if these where available when I initially got my piercings I never knew about them), but after such a long time without wearing piercings it is tight getting one of my standard earrings in, so is it possible to get flat backs that would fit? I have no idea what gauge I was initially pierced with - whatever they used in the gun at the mall.

I’m also getting bored with my nose ring and would like to find another 14k gold screw stud with my birth stone, but again, I need recommendations for reputable vendors. Do I need to know the gauge for this? I don’t know what size needle was used, but I had it professionally done at a piercing shop.

I’d appreciate any help or suggestions.