Metrics That Matter for Partner Account

You'll probably find the information here most useful
https://onlinehelp.explorance.com/mtm/Content/introtopics/headmspartners.html?tocpath=Channels%252C%20Learning%20Partners%20and%20Certified%20Instructors%7CMicrosoft%7CMicrosoft%20Learning%20Partner%7C_____0

and this document if your organization is just signing up 
https://assetsprod.microsoft.com/mpn/en-us/metrics-that-matter-overview.pdf

The account credentials itself is the same for your already existing email address, but when you login to MTM you pick which organization and access you login as.

Your contracted (and any internal ones as well) MCTs should already have accounts set up from when they joined the MCT program- if not have them set them up as such. You would then associate their account with your org using the admin level access.