When animating bosses try to make sure there's always movement, even if it's just a small movement try to always keep the boss in motion, whether it's a scarf or an eyebrow constant movement makes a huge difference, although it can be more time consuming so be prepared for everything to take a long time.
You could check out the pa discord there are tons of people who'll be able to help you out. And you could also watch Zlucky's tutorial series on the basics.
