how do I transfer data from my windows to Mac if I have already setup the Mac book

By using the Windows Migration Assistant. The only link I have is Download Windows Migration Assistant v2.2.0.0 (Mojave).

what i have is several external hard drive that reads both Windows 10 and MacOSX and well as a USB stick.

And networking these 2 is not solid, well I can't network these systems reliably through a network, I had my MacBook read my Dell XPS for 5 minutes in March then the connection was lost for good.

i hope this helped, or answered your question.