I learned how to do my own last year. My last salon manicure was in September, now I have a great kit and change my polish every ten days.
YouTube is your friend. The back to basics videos from Naio nails are very helpful. Watch lots of videos on prepping and applying polish so you are prepared. Also join the U.K. based nail tech groups on Facebook, Love for Premier Gel is good.
Get the best lamp you can afford. The cheaper ones on Amazon will not cure properly. This one is great. It's exactly the same as the one that The Gel Bottle sell for 3x the price. Its great because it has a low power mode, which stops heat spikes. It's often on offer. I've seen it as low as £29.99
Led Nail Lamp, SUNUV 48W Professional Nail Dryer for Gel Polish Curing Light Machine, with Automatic Sensor and LCD Display for Home and Nail Salon https://smile.amazon.co.uk/dp/B07XRN87XJ/ref=cmswwrcppapiglttfabcK5S6RES0DVBAD4SV0X55??encoding=UTF8&psc=1
You will need some wipes to remove the tacky inhibition layer Mylee 200pcs Gel Polish Prep & Shine Wipes, UV LED Gel Nails Soak Off Varnish & Sticky Residue Remover, Cleanses Nail Plate Pre-Manicure Pedicure and Removes Sticky Inhibition Layer https://smile.amazon.co.uk/dp/B019NCIZDO/ref=cmswwrcppapiglttfabcD1283ZTA1BRRDP0B8SVF
Get a load of files of varying coarseness. Again you can get these cheaply on Amazon. The Chinese brands are fine / just check reviews. You will also find little tools like cuticle pushers/snips, tweezers, brushes and a bottle of acetone helpful too.
After a few months I bought myself an efile and some decent bits. This makes removing the polish and prepping the nails super fast.
I almost exclusively use Premier Gel polishes. They're good quality and the range of colours is brilliant. The facebook group is great for seeing the colours on real hands. Only buy Premier Gel on the weekend! They do weekend sales with 40 or 50% off. I do a layer of builder gel, two colour coats and a topcoat. I've also brought a loaf of foils and nail art supplies which I experiment with occasionally.