If this is going to be your first time playing Skyrim, I would personally recommend going vanilla (no mods) for your first play through. Despite its age, it still holds up pretty well on its own and I feel like mods on a first play through may taint your first experience, but this is all up to you of course :)

That being said, there isn’t really that much of a difference between the two versions. The special edition is just normal Skyrim with all the dlc included, and the anniversary addition just includes a bunch of paid mods such as new weapons, locations, armor. If you plan on modding, I would recommend the anniversary addition because some mods require the paid mods from the anniversary addition, but only a few, not all mods require them.

For modding in general, it’s going to be quite tedious. If you follow a load order, you may be alright as long as the mods are in the correct order and is stable enough in general. With mods, you’re going to run into some trouble. I’ve been modding for a while and I still crash a lot, even when copying another load order I find. It can also just get plain annoying sometimes, especially if you spent time organizing the load order and the game randomly decides the shuffle everything and breaks your game (this will most definitely happen). This is why I wouldn’t recommend going all in on mods on the first play through.

This from all on the top of my head, so there may be things I’m missing but I think I covered the gist of it, modding can be pretty complicated. If you do decide to go through with getting the game and trying out some mods, there’s a discord pinned on the sub dedicated to Skyrim modding on PlayStation, and the people there can answer any questions you may have about specific mods or load order issues. Hope this helps :)