My tips for it are:
-When shuffle time comes up prioitize what you need. Making sure your at a good level is important, so whenever shuffle time comes get the exp boosting one. Only time I would say not to choose that is when a new persona comes up.
-Get a feel for changing tactics in battle because they are important and depending on some battles not changing tactics can be the death of you.
-If you can reach the end of a section of the main dungeon before the next full moon comes you'll be pretty good for the main boss, just make sure to save a day or two before then in case you need more levels
-Grinding too much in the beginning in the game can cause characters to get sick or tired. If they are tired they'll perform worse in the dungeon. They'll usually give you a prompt when that start feeling tired in a dungeon so you can leave before that happens. However if you keep pushing them they will get sick and will be unable to help in the dungeon. When progressing further in the game this will take longer to happen.
-It may be annoying to keep up with, but try to keep all party members around the same level. I made this mistake with only keeping my main party leveled up and by time I reached the end Final Boss messed me up a bit, but I was still able to beat it after a couple tries. Just makes the game a bit easier to have more options.
-You can refill HP and SP without using items if you go back to start of dungeon.
Thats kinda all I can think of right now, but have fun with it, may be kinda hard to get a grasp of at first but its good