I use the PhiloSophia body and ASR head. Because you can buy them both for 1280 linden (about 5 USD at the time of writing this), it's a wallet-friendly option for people starting out. There's little clothing made specifically for this body, but in my experience clothing made for the more popular Lara Maitreya body fits this one as well.

EXiA - Lolita dresses and accessories, also sells kimonos.

{Rosier} - Tons of lolita and adjacent j-fashion.

spectacledchic - More casual cute fashion.

Magnum Yoshikawa - Extremely cheap basic cute fashion. I bought my first outfits here.

Bonbon - Realistic (but fun) hair with customizable colors.