Technic, FTB and ATLauncher have their own repositories for packs. There's also Modrinth . Specific packs may also exist on other places like Github or their own websites. With that said, something like 90% of the packs you'll want to play are on CF unfortunately. I think most people use the CF launcher to install/update packs, then MMC/Prism/vanilla to actually play. More on reddit.com

The easiest way is probably to use the Curseforge app (I recommend the standalone option). Install it, then on the left side click on "Add a game" and add Minecraft. Once that's done, you'll be able to browse for mods and modpacks within the curseforge app and automatically install them. After installing a modpack, press launch, then a minecraft launcher window will appear prompting you to login. Insert your minecraft credentials and press play! More on reddit.com

They way CurseForge distributes modpacks is to not include any mods in the pack's download. Instead you get a manifest file which the launcher(s) is supposed to read so it knows what to download and assemble the modpack when you import the modpack. A manual install would require downloading each and every mod manually. If a modpack has a server file download then that usually does have mod files in it, which will get you most of the way. You'll also have to download and install Forge, organize the modpack's files, set up the vanilla launcher, etc. It's certainly possible, but it's a bit of a time sink. ...or you could install one of several modded minecraft launchers which will do all of that busy work for you automatically. I'm perfectly happy with Overwolf's CurseForge App. GDLauncher has the most of the same features and is 3rd party. A lot of people recommend MultiMC, which seems to be getting the ability to download for just about any source (CurseForge, FTB, Technic, etc.) and I believe was made by a current Mojang developer working on Minecraft. Converting an existing modpack already on your computer to be opened in the Vanilla launcher is way easier. More on reddit.com

Free hosting is made for few players on vanilla Minecraft. not for 400 mods modpack with 10 players More on reddit.com