We host a variety of modpacks so the choice is yours! Everything from 'kitchensink' packs to hardcore, expert packs. You can try playing Revelations or any of the DIrewolf20 packs if you are looking to explore mods on your own. If you are looking to dive into the deep end and play an expert pack, I suggest Nomifactory or Dungeons Dragons and Space Shuttles.Or if you want to sink 4000 hours into a pack and lose your mind, I suggest Gregtech: New Horizons These expert packs have a questing system so they 'guide' you on your way to the endgame goal.
There are a few modpacks that are questing packs that aren't necessarily expert packs, in my opinion, like Sky Factory 4, Oceanblock, or either of the Stoneblock packs.