I’d first work out what group/s you like. So floral, oriental , fresh and woody. Pick two perfumes from each group.
Good starting points:
floral: Daisy(Marc Jacob’s), Flora range (Gucci) or flower Bomb (Victor and Rolf)
oriental: scandal (Paul Gaultier) , Black Opuim (YSL)
fresh: White Tea(Elizabeth Arden), light blue ( Dolce and Gabbana )
woody:CHANCE EAU FRAÎCHE (Chanel),BORN IN ROMA DONNA (Valentino).
You can also add fruity or food scented perfumes but I’d start with the above for your first grown up perfume.
Ive picked the above based on the fact you could go into Boots or the Perfume shop and easily find them. I find Jo Malone can be added to the “fresh” category. Aldi do similar dupes to those so if you do like the cheap versions, you can pay for a sample from places like eBay of the real deal or go to a shop.
I would go in with a list, like the above, and pick two to try at a time. You’ll get overwhelmed otherwise. narrow down to a category you like and then pick one and spray it on your skin. Give it half and hour and if you still like it, that’s the one to buy.