This one can be hit or miss. If you have an ADR booked at the resort they will definitely let you in and you can tour the resort while you are there. AKL is an excellent choice as there is a lot of fun to be had while you are there and the dining is top notch.
If you just want to look around it’s really up to the guard at the entrance. Normally as long as it isn’t peak season where there might be parking concerns they won’t have an issue with it, but there is the possibility you’d be turned away.
Another fun choice might be to book a dinner at either the Hoop De Doo Revue (pricey but fun) or Trail’s End (one of the best budge Table service on property) where you can have dinner and then stay for the Chip & Dale sing along and campfire movie which is free!