For vanilla minecraft, the default launcher from Mojang themselves is fine but lacks support for mods (since you have to download those seperately alongside the mods you want to add). However, if you are serious about modding the game: Prism, ATLauncher, Curse Forge are preferred since those have the loaders (Forge, Fabric) integrated.
Yes you can but it’s kind of hidden.
In Prism, it’s super easy to set up an instance, throw in a mod loader, and filter, download, and update compatible mods in the app. It also allows you to choose and configure the Java version easily per instance, view logs, and export instances.
It also has the cat button, which shows a cat :3