I had a few newbies and we do have to start somewhere. So long you have good communication with them and they understand your house rules or special circumstances, it should be fine. Think of it as your opportunity to win raving fans for your listing and a great airbnb experience for them! I allow instant book and have no issue (we are on the premises as our listing is an ADU on the side of our house). It may be different for a whole house listing or if you are off premises or out of state.
I’ve not had a bad experience probably because we communicate well with our guests.
Some people however do not read the check in instructions and end up going the wrong way. I gently ask them if they read the check in instructions as it was carefully explained with pictures and captions how to park, walk to your suite, enter the suite, etc. We had people wander up our back stairs, go out the backyard to the gate behind, and enter the wrong gate as they didn’t read. It’s always good to check in with them or set automated messages because of this potential issue.