I have Androgenic Alopecia and wear wigs. There are two really good and professional wig companies who also have shops, but too far away from me, so I have ordered online.
Simply Wigs
Joseph's Wigs
They are incredibly helpful and empathetic on the phone for advice, and their websites have plenty of free information. There is no problem returning a wig if it's no good, but obviously it's best to spend some time measuring your head, choosing the right colour, etc. There are dozens of colours and hundreds of styles to choose from.
I can't afford the human hair wigs so have had the synthetic ones, but honestly they are so realistic that even my hairdresser couldn't tell. Because I was used to having thin hair for a long time, I asked my hairdresser to thin out my first wig so it wasn't too much of a change.
If you like the look of a wig, then check it out on YouTube. There are hundreds of wig videos. It's amazing how different a wig can look on different people.