Blender to Unreal - some help would be appreciated :D

I am usually working in blender and would like to make a level environment in Unreal but I am a bit lost with some particularities of working in Unreal.
I was hoping someone can help me out here as I want to really push myself and finish this level design. I have built everything all in blender, walls, pillars, ceiling, sculpted 2 trees and modeled the plants and flowers I would like to use. Whole deal, and also created the materials in blender…
Although I do not have any actual experience with game design or level design, I really want to get this done, and with all the tutorials out there I cannot find the answer to this question…

Would I have to bake every element in blender before I import it into Unreal? And is it ok if I make my own plants and trees and then import these there?

And lastly, does anyone have any advise what would be best to check out for this kind of buildup?

Appreciate any help I can get :smiley: