new site creation form on multisite network

Hey,
I am new in wordpress multisite network but I am setting up a multisite network but I am having some issue on new site creation form on my network.

I am setting up a memebership website on multisite network and my
First requirement is when someone access my membership hub page then they will see a button which say them ” Create Your Site” and then they will go to the new site resistration page and other people who does not have the membership access they do not able to create new site on my network.

Second Requirement when they create a new site and back to the membership hub page then they will see another button call ” Go to your site dashboard” and when they click on it then they will go their wordpress dasboard.

Please advice me for these issue. If I make any wrong on my requirement then also advice me.

Thanks in advance,
samir chandra halder