Share 'Questions regarding SF to Half Moon Bay walk'

Hi, My friends and I are walking in April. We plan to walk it from Half Moon Bay to San Francisco as some of us a concerned about  walking on the sand on the first day. I'm wondering if anyone else has walked it in the reverse and if there's any issues with that. Also, there was some concern about walking on HWY 1. Can anyone elaborate on that? We have reservations at the Half Moon Bay Inn on the…