How to fix: Merging layers still differentiates between layers, lasso tool, and creating symbols

I recently started using Adobe Animate for a school project and am having some trouble with combining layers, using the lasso tool, and creating symbols. I draw the objects on Adobe fresco and then export them to Creative Cloud, and then into my person library so I can use them in my animation. I have a drawing of a hand that is made up of three layers, and when I merge them, I am only able to move around and delete on of the three layers, not all as one. Also, when I use the "break apart" tool to be able to use the lasso tool, and for example I delete my selected part, it deletes a whole layer (out of the three), and a part out of the second one, and nothing out of the third. Instead, I want it to delete my selected part. Additionally, when I create a symbol, how do I make it it's own layer?