Buying paper and art supplies is such a weakness of mine. The best guideline I can offer is to look closely at the art supplies and feel them. Some of them will be more appealing to you than others- maybe thicker, textured paper, firm chalk pastels that don’t easily rub off on your hands, or shiny, smooth graphite.
When art supplies come in shiny boxed sets, it makes me worry that they’re trying to hide a lack of quality. If they’re sold individually and you can handle them and look at them, it usually means the manufacturer is confident in the product and doesn’t have anything to hide. Also, sets are often sold as gifts (my relatives used to always buy me nice gift sets for birthdays and holidays, and they’re really not interested in art). Individual items are the kind of thing an artist might buy for themselves, to supplement supplies they already have.
A couple colors to look for- in watercolors or acrylics, look for sets that have cyan, magenta, and yellow. These are the purest primary colors; you can mix them to make yellow, blue, and red. There’s no reverse process for mixing these colors out of others, and they can be the building blocks of any painting. If paints aren’t available in these colors, to me it says that the paints are for casual hobbyists.
Other “building block” colors to look out for are burnt sienna (a warm, earthy reddish-brown) and burnt umber (coffee-colored brown) which you can mix with primary colors to make almost anything, from skin tones to realistic earth tones to warm lighting.
I guess I do have favorite brands. Windsor-Newton makes water-solulable oil paints, which are pretty awesome and versatile. You can water them down to the consistency of watercolor (and on a gessoed surface, which is awesome) or you can build them up in layers like oil paints. They stay wet for a long time in layers, but dry fast when watered down. It gives you a lot of control. Prismacolor nupastels are my favorite chalk pastels; they’re very firm and don’t crumble or get chalk dust all over the place. You can draw with them and not have to worry about smudging the drawing or spraying it with hair spray. Liquitex acrylics are also pretty solid and I have a whole bunch of them.