Amateur with clothing brand manufacturing questions!

Is it best to use a CMT (cut make trim) or fully factored manufacturer when starting out?

If I decide to go with a CMT, do they produce and attach the labels and tags? If they don’t, what is the best way to source a label maker and how do I efficiently get the production of garments, labels, packaging, etc. accomplished without greatly increasing the total cost? Do I pay for shipping when items switch hands?

In the first year of business, how much product/ how many units of each style/garment is reasonable to manufacture (I don’t want to order too much)?

Working with a CMT do they want you to have garment patterns ready or can they work with you to develop them?

What is the best way to source quality fabrics and unique buttons and zippers?

Thank you! Apologies if some of these questions seem silly but any help would be greatly appreciated.