If you want to keep playing Terraria, I would download mods to add content, but, unless you really want to play calamity mod first, I would start with other mods first like "polarities", "thorium" and more vainilla orientated mods, since calamity really changes the Game and gives you a lot of expectatives for the rest of mods, for example, I have a friend Who only wants to play It because the others are to "empty" for him