new in-person office job starts monday at 8am, no reporting details today and it's already off-hours, do I have a decent plan?

• accepted offer letter, done I-9 and all other papers they asked for.
• got general HR email today (friday) about how to get my badge on monday and the other half of I-9 done, but that starts at 9am.
• onboarding meeting is online on monday at 10.
• in email, it says to email the person who interviewed me for reporting details. I did, but no answer and it's off hours now on friday.
• No where in any email does it specifically say what time I start, only the starting date, so I'm going off the hours they told me during interview.

My plan is to show up 7:40-45am at the office place i interviewed at, tell the person at the front who I am and is there to report for first day of work and ask who do I report to.

It's my first job and I'm seriously just going in feeling like a kid waiting in checkout lane for mom to get her last-minute forgotten item.