First, check out my partner's Wig Seller Masterlist, though she hasn't updated it in a while and could probably add a lot of Amazon and Aliexpress brands that she likes.
Wig fit is such a personal thing that a brand that works for one person might be terrible on another (Arda gives me tension headaches, for example, but a lot of people swear by their fit), and what fiber you like is also personal and depends on what you are doing with it.
That said, if you're looking online for cheaper wigs, here's some tips (and me rambling about styling and wearing tips by the end lol):
Look for "rose net" instead of "button net." These terms will very likely not appear on the listing, as they are translations of Chinese terms and hardly anyone uses them in English (instead this just doesn't have a name :']), but the difference is in how the wefts are attached. Rose net will almost always be higher quality and more comfortable.
Rose net on left, with the individually spaced wefts with strips holding them, button net on right, with wefts sewn to a full mesh cap.
Look for measurements of the wig. They likely won't have full measurements, just circumference, but even that will help to know if it will be way too small or large.
LOOK FOR REVIEW PHOTOS. Even better if they aren't super filtered and show the inside of the wig as well. colors can be off, the fiber can be much shinier than you expected, it can be much thinner than expected and show the tracks, etc. Review photos will show you what product actually arrives.
Start with simple styling. You don't need a crimper unless you're doing styles that require one. You don't need to do a helmet wig. A flatiron or steamer (or both lol), some thinning shears and regular shears, and a comb will be your best tools. Look at tutorials, and not just the TikTok style "here's quick cuts of my process and not actually explaining what anything is" type of "tutorial." Look at older tutorials in addition to newer ones, since wig styling trends change, and something in an older tutorial might be the styling you actually need.
Another styling tip: wig hair is plastic. This is a material that, unlike real hair, holds style upon being *cooled* in a specific position. You can heat it all you want, but if you don't hold it in place until it's fully cooled, it won't hold the style. curlers, pins, clips, etc. will be your best friends there.
For wearing: get a wig cap. Stocking type that's closed on top vs fishnet type that's open on top is up to personal preference. Get something in beige or close to your skin tone rather than black so it's more versatile under different wigs, since a black one can show under a light-colored wig (they often throw in a free one with wigs, and sometimes these are black). If you have long hair, do French braids coiled around your head or pincurls. I swore by pincurls when I had hip length hair way back in the day, but basically you want something that will distribute the hair evenly around your head and also allow you to pin into it to help secure the wig.
Some people swear by wig grips (either velvet or silicone, though if you do silicone get the name brand Wig Fix, it really is that much better), some people hate them. YMMV.
Hope that helps! Good luck :]