Are there items in Pokemon Unite?
Yes. Compared to other MOBA games, items are not as important to the game. Instead, strategy in Pokemon Unite has more to do with your positioning and evolving move set.
There is a lot of potential in items with this game, though. Certain items can be held by your trainer to be used with long cooldowns (similar to Summoner Spells in League of Legends). Other items can be equipped to your Pokemon to buff certain stats.
That said, if you can quickly upgrade an item to lvl30, it will give you a massive advantage in early ranks. You might be able to do 20-30 extra damage per attack or special attack, which is a big deal until the other players catch up to you.