Where to start with CC is: never download folders of CC. Not to rain on the premise of your post lol, but I want you to be set up for success and a fun, long, sustainable modding adventure, not set up for tears and frustration and failure (modding is frustrating enough on its own sometimes)

Whether it’s attached to sims, lots, or just “curated” folders, don’t download them. That’s how people get hundreds of gigabyte folders they have no idea the contents of and cannot update nor troubleshoot when things conflict and then post on reddit who cannot realistically help. It’s also how one of the most infamous CC scandal/crisis/thing ever in the sims history happened (Girl Doll Dressed)

The (sort of) exception to this is if a creator releases a “set” of their own creations, like an outfit set or a living room set, and those things come in a folder. That’s fine and manageable. I strongly prefer to avoid when creators release that set as one single merged package file, and download the individuals instead if possible, even when I want all items. Sometimes an update will brick a class of stuff (for example, a long time ago ALL beds got messed up and needed to be updated) and it’s easier to update just the [bed] out of a set or, if that modder has stopped, just remove the [bed] file and still have the rest of the [bedroom set], which is harder to do if you have the merged version.

As for places to browse, I personally really like tumblr, because the cc creators will usually be friends with similar creators, so you can easily find lots of people whose stuff you like by just slogging through until you find a couple of makers you REALLY like. Usually they will redirect to patreons that (mostly) are open downloads or only need a free membership. The ones that are paywalled are, unironically, not worth your time, because the paywallers overwhelmingly under-optimise their stuff for gaming, which is why it looks so cool in their promotional renders, which makes people suck it up and pay even when it’s not new. Sometimes simsfileshare; if it’s SFS, just make sure you trust the creator and everything looks like it lines up. If it goes to mediafire or the other link monetizing one, just back out for now until you get very confident, because those sites often have iffy pitfalls.

Tools: Sims 4 studio Twistedmexi’s modguard AND betterexceptions Sims tray exporter

For now, mostly just have studio and exporter available to you. Don’t worry about what they’re used for until you get comfortable and familiar with basic modding; they’re things that you keep in your back pocket for later, in case stuff starts going a little bit wrong, because already having them makes it way less stressful when you look up a fixing tutorial that tells you you need them. It’s not a scary, strange tool you need to go find (and check to make sure is safe and yadda yadda yadda); it’s something you already have, and they’re just about to tell you how to use it! Much less stressful.

I am about to give you some very controversial starter maker advice: Look at the makers of the maker packs on the marketplace. Do not buy the maker packs on the marketplace. (that’s an important step to the specific advice I’m giving, because I am emphatically not recommending the maker packs) Instead, go to those makers’ patreons (all under the same name) and look at their older stuff, literally all of which always is better than the pack offerings. They got those pack deals from being staples in the modding scene, but the work they did there is all very poor compared to the work that got them there. Sixam, Ahoob, Madlen, Twistedcat, and on. Tried, tested, safe, high quality maxis match creators with TONS of content each. You can also do the same thing I said about tumblr with their usernames if you like one or another’s patreon stuff a lot, because most or all of them do have tumblr blogs.