Need Rocky Mountain Nat’l Park Advice

I accepted a new job and don’t start til midmonth. Booked a flight to Denver and Turo to go clear my head for a few days next week. I haven’t been since this new Vehicle Registration and Online Reservations stuff began. It looks to me like it doesn’t all start until Memorial Day but I don’t want to be left holding the bag. Any way, I’ve hiked all over the East side of the park and stayed in Estes plenty but heading to the West side this go round. Any advice on new rules/regulations to watch out for and good hikes/campgrounds is much appreciated.