Public suiting tips for a beginner?

Hi! Im currently workin on a fursuit head, paws and tail and im looking for tips on fursuiting! Im also looking to see if anyone has an experience with these companies and knows whether or not they are okay with fursuiters, ill still contact them beforehand to make sure but yknow.

Is Sainsbury's fursuit friendly?

And

Is HMV fursuit friendly?

Ive seen other posts on this topic before but they're mostly targeted for tips for people over the age of 18, whereas i am not.