So it's finnicky but yes there's a "limit". Nothing can be enchanted past lvl 39, after that it just says "too expensive" in the anvil. Depending on how the enchant was made too, say by book, can drastically increase that too. So for example, putting Mending first on a sword might cost let's say 5 levels. The next enchant, let's say Looting III, might cost 11 levels. This will keep increasing on that one sword until it can no longer expect anymore because the next enchant exceeds lvl 39. The minecraft wiki breaks it down some more but that's the jist of enchanting.
IMO, in your enchanting table, look at what might go on you sword, in this example. If the name isn't something you want, enchant a book at the lowest level, and then put the sword back in and see again what you might get. There's no guarantee you'll get multiple enchantments at once, but you can guarantee at least one and not have it cost bonkers. Hope this helps!
