Welcome, Gizmo! n_n
The parks go on the folder "Save" on your game folder. If you didn't touch that folder at all then it should be in AppData but can't remember if it was on the subfolder "Local" or "Roaming". Meh, just right click the shortcut and you probably know the rest now, lol
About the "mods and texture packs" question...
I don't really get the question but maybe i think i know what you tried to say.
Mods could be harmful to other online players if said mod has a something that could ruin the fun, like giving the user points without any effort (like it happened before) or freezing a game indefinitively (what used to happen with freecam before).
Now for texture packs.. If you replace the
actual files then you have to worry about backups and replacing every update, unless it is a TexMod/uMod .tpf what you're trying to open.
Any question, feel free to ask!
I'll prolly see you in-game in a couple of months too,
brah.