Cycling shorts are meant to be worn commando. Underwear can cause chafing, even if it doesn't have seams.

Hair removal leaves most women susceptible to ingrown hairs and infections. I usually keep the hair trimmed to 1/2" or so to avoid pulling and tangling.

Make sure your saddle is a good fit (there are several threads here on saddle fitting), but if you're still experiencing chafing, many if not most people use a lubricant like Body Glide, shea butter, or other chamois creams for longer rides.

Welcome to TE.