Finding Legit Dresses

Hello there! I’m getting married in February. Does anyone have any suggestions on where to find really nice bridesmaids dresses for women and junior girls? I am also looking for a flower dress with sleeves for my soon to be 1 year old. I’ve tried looking online on some apps and I’m not sure which ones to trust. Congrats to the beautiful couples getting married or the ones that have already tied the knot!!!!!