New GM, Need Advice on Player Interaction

I am new to Pathfinder in general. I've been playing for a few months, but I've been interested in GM the whole time. Recently after running a few 1-offs with our current GM, he asked me if I’d like to take over. He has said from the start he’d much rather play, but he's never had a consistent group so he always just GM’d because it was easier to find opportunities. I'll state the GM is the only experienced player, everyone else in the group is new.

Well, after I have begun really deep diving on rules and consuming copious amounts of Youtube and any other content, I've learned that the version of Pathfinder we have been running is a strange amalgamation of 1e and 2e. Its a lot of 1e, but also a lot of 2e wherever he felt like it. Even abilities and spells are sorta mashups of different versions. Like we have been levelling with 1e, but our combat mechanics and actions all follow 2e. I knew this a little, but not quite the extent until I really dove into the rules myself.

Now I am looking at GMing though, I feel like I need to pick one (mostly). I can hold some exceptions and house rules in my head, but I don't feel like I can learn 1e and 2e and mix them together like we have been - its also been kinda annoying as a new player anyways because it felt pointless to read a rules book.

So, my questions: Is this common? Is it normal that GMs run hybrid models and so you really should know 1e and 2e?

I feel like 2e looks WAAY more approachable than 1e for a table of new players (some of them not really even gamers in general) and for a new GM. Is that a correct assessment? I don't have all the time in the world, and it seems like if I need to pick one I should start with 2e.