I am part of a project that is starting up that will have a client executable and a server executable. We are using git to help keep our team updated with code and this is the f
You should use a single repository, because it can hold multiple projects/solutions/anything else that builds an executable.
In general, I would organize it the same way that you would like to have it organized locally. There is no reason to deviate from what works for you to accommodate git.
I would suggest setting up a github repository that all parties may access.