A relatively new player here. Which units that I should focus to easily clear contents?

Hi, new player here since Senran Kagura collab and decided to play this game a bit more seriously after I got lucky on my Bunny Eclipse pulls. So, what units that I should focus building now to easily clear events and contents? Any future units that I should pull? And from the shop, is it wise to spend all of your points for new unit / dupes?

Any advice is welcome. Thank you!