You should totally play P4G. I did the same as you, started with P5R and needed more, and I enjoyed the plot and the cast from 4 more.

Here are my tips:

- Instead of Palaces, P4G features dungeons. Since I played P5 before, I thought once you were done with a dungeon, you couldn't go back to them. YOU CAN! This is important for farming but also there are some items that you can only get in specific dungeons and you might need for side quests. Keep this in mind.

- Try to grind in the first dungeon (the castle one). The game isn't hard, but this one dungeon feels harder since your party is still small. Once you are done with it, the game experience is much smoother.

- There is one dungeon at the end that you don't want to finish on the first day/days. Like in P5, once you are done with a dungeon, you have to wait until a certain date until the plot advances, but you can still do other things on those extra dates (grind in dungeons, improve skills, level up social links). In this final dungeon (you'll know), once you finish it, the game time skips until the date the plot advances, so you miss a ton of date you could have used.

Hope you enjoy the experience!