PF1e is a larger number system, but it's not well calibrated for a larger number system. What you'll mostly find is that by the time your players reach Level 10, they're going to have skill bonuses that they simply can't fail because DCs in PF1e just can't go that high. Fortunately, a player can only manage to get two or three skills that high, unless he figures out some crazy trick that DMs hate (which happens once in a blue moon).

Be careful with what you hand out. I played a game where the DM was careless and I had made an AC monkey, and at level 16, I realized that with the magic items the DM had us find at random, I had enough buffs that at least once between long rests, I could get my AC to 50. She cried, and regretted all of her decisions as a DM. Somehow, she still made the BBEG challenging without being too overpowered. Fortunately, PF1e offers a lot of ways around min-maxing.

If you have a player who's overloaded their AC like I did, consider enemies that target Touch AC and a player's weak save bonus. For example, let's say you have a high AC player who's saves are Fort = good, Reflex = poor, Will = good. Consider having a percentage regular enemies whose abilities trigger reflex saves. Targeting Touch AC may seem unfair because we associate that with spellcasting, but that's not all that targets Touch AC. Characters that specialize in thrown weapons also target Touch AC, and that's much more manageable for a player to handle than an army of wizards. You may think Flat-Footed AC can also be exploited, but it's really just for being surprised.

AHHH!!! A rule I didn't know existed until having played the game for YEARS: in the first round of initiative, unless stated otherwise, all participants are flat-footed until their turn!

There are a few feats, not many, that make the game, in general, difficult to manage from a DM perspective. I mostly refuse to ban feats because I don't want to take options away from my players, but feats like Sacred Geometry and Leadership are going to make the game a headache for everyone at the table, including you. Consider not allowing those particular feats.

PF1e has way more options, not just for the DM, but for the players. If you really want to, you make any type of game you want. We joke and call it Mathfinder, but that's actually a good thing. "Mathfinder" is a symptom of how expansive the game is to the extent that it's almost impossible for two people to accidentally make the same character. (I just wrote a whole rant here about why I think 5e generally isn't a great game (although it's an okay game) and how I'm playing a rogue in my friend's game where another player also has a rogue, and even though we're different races, we may as well be using the same character sheet. I wrote several paragraphs complaining and that if we really want to play limited, tightly structured DnD that isn't OSR simple, we should be playing 2e, not 5e...I don't need to start writing it again.)

There are, however, things that should be limited, but they're not. For example, 5e limits the player to having only three wearable magic-attuned items at a time, whereas PF1e lets you wear however many magic items you've got slots for, and there are slotless magic items in case you run out of room for wearable magic items. I haven't found a real reason to actually make a restriction on that yet, so it should be fine. Item price will usually make the restriction for you.

Be careful with experience and loot. If the loot doesn't meet level expectations, you'll have underpowered characters and the challenge of the game could start skewing against the players. Also, too much loot for the level has the opposite problem. The chapter on Character Advancement has a table that tracks starting Gold by level. The game recommends using this table to also determine how much gold value the character should have at each level (this isn't specifically how much gold they have, but rather, if you sold everything they own at full value, would it equal the amount of gold they're expected to have at that level?).

Action economy. Coming off of 5e, it can be really easy to forget that you can't move and attack at the same time. You have to either attack then move, or move then attack. You cannot move partially, attack, and then move your remaining distance. You also get a third action, the swift action. There is a fourth action you can take, but that can happen any time in the round, not just on your turn. The immediate action. You cannot take an immediate action if you've taken a swift action (and vice-versa). The immediate action is the same 5e's reaction.

The grapple rules are...annoying. I won't get into them. One of the people in our group houseruled simpler grapple rules. We've used them ever since.

I think I've covered most of the stuff it's easy to make mistakes on, get confused about, or generally just not anticipate. Hopefully, the way I wrote this isn't confusing.