I think as long as you're aware of those differences it should go a lot smoother for you. Just try to let go of the "well I've always done it this way" which I know is easier said than done. I like to bring up familiars as a good example between the two systems. Apologies if this comes across as over explaining or anything, just wanting to be clear and I really love this system lol

In 5e, I'm sure you're familiar, you cast the Find Familiar spell and pick from a list of stat blocks provided by RAW or by your DM. Boom, you're done.

In PF2 though, you create your own familiar from scratch, and you can do it every day. So it's a little more involved but it feels truly unique to you and your imagination since there's no limits on what it can look like. Here's a link to the rule itself (another bonus to PF2 is they host all the rules online for free), but basically all you need to know is:

Each day, you channel your magic into two abilities, which can be either familiar or master abilities. If your familiar is an animal that naturally has one of these abilities (for instance, an owl has a fly Speed), you must select that ability. Your familiar can’t be an animal that naturally has more familiar abilities than your daily maximum familiar abilities.

So if we're making an Owl familiar like they show in the rule description, you'd select Flier and one other ability you want your familiar to be able to do such as the Speech which would allow it to speak a language you know. Or, you could pick Manual Dexterity if you want it to be able to do more fine tuned motor skills. Some classes and feats you select will allow you to pick more than two abilities if you want to make your familiar more powerful. So you could as you level up have that Owl familiar with the Flier, Speech, Manual Dexterity, and then combine that with Lab Assistant for a perfect recreation of Merlin's Archimedes 😄

Or you could choose any other number of abilities to take your Owl familiar in a different direction, like Burrower for example. No reason you can't make a tunneling Owl, because why not? It's your familiar!

Things like that, people say it's more complicated and I guess you could say that it is because there's more options. But I feel it's still very intuitive, easy to pick up and gives players soooo much more empowerment over their characters.

I would love to try different systems for oneshots I run, though, but then to start with I think they need to be very different from D&D 5e so I don’t get things mixed up. Any suggestions? 😊

I have a looooot of systems I could recommend tbh lol

To help narrow it down are you looking for something of a specific genre like scifi, fantasty, post apoc, etc?

Actually, I'll throw one right out of the gate that you might like based on the vibes I'm getting from your comments and you can start today if you wanted. It's an indie solo journaling RPG called Apothecaria (Link here). You play as a witch in a village that makes potions for the villagers that come to you. You go through week by week to forage for ingredients, brew the cure they need, and sell it. Instead of dice it works based on a normal 52 card deck of cards and what happens is based on the card you draw. I only recently started trying solo RPG's like this but it's been a fun one.

Let me know if you want more recommendations based on if you want something more fluffy or more crunchy or if there's a specific genre you're interested in. I love talking shop 😄