>>9157944If you're really getting a MTM Barbie, there are hundreds of video tutorials on yt for clothing and other stuff! From the most basic clothes to more complex stuff. It's hard (at least for a hobbyist like me), but when you get it right and see your doll dressed cutely with something that you made yourself, it feels so rewarding!
Also there is Etsy for patterns and handmade clothes. Also Aliexpress, you can find some nice stuff in there through a bit of digging.