I am also a new nail tech, it is a bit of a minefield! Watch The Nail Hub (Liz Morris) for a bit of helpful guidance; her video playlist called fundamentals is excellent. She mentions how certain colours are more difficult to cure if the ingredients aren't right, and so she usually buys certain colours from a brand to test them out before committing to them. If you have a good lamp that will cure all brands, this should be a good way to test them out. I remember her saying that some companies are more selective regarding their ingredients in terms of safety (and for the curing problems I mentioned), and explained why it's so important to do your research first. I'm currently trialling The Manicure Company, Akzentz and Artistic. I really like Akzentz out of the three, but it happens to be the most expensive, typical me with expensive taste! TMC is very good value though, and they offer a really good range of colours. I really like their builder a bottles and they have thought carefully about the aesthetics; the colour of the gel polish is in the lid, so it's easy to find them if you store them in a drawer, (cool dark place is always best.) They are 100% pure gel, as are Akzentz gels. Artistic Colour Gloss is not 100% pure gel, it's more like a hybrid and contains solvents like in polish. It's very runny and it makes it easier to flood the cuticle, so that's something to bear in mind, because HEMA and other chemicals must not touch skin, they can lead to sensitivities and allergies. I find the lighter shades have the best coverage, not so great with dark shades, but then I don't have their very expensive lamp so can't really complain. That's where lots of companies can catch you out; they want you to use their system - all of it. It means you have not argument when you call them to complain their gels won't cure! Also I got a bit annoyed when I discovered they are selling their old style bottles on Amazon. Lost respect from me!
Maybe go to Olympia next weekend (if you haven't already booked!) or another trade show? You can check out all the suppliers and ask lots of questions. Good luck x