Slitherine

I have downloaded and installed the GS Mod, not sure if ti makes a diffrence in the answers to these questions 1st placing German units in North Africa do I have to wait for a set date or can I simple place newly built units in Tripoli etc? If I have to use transports I would like to escort them with naval units do I need to have the naval unit adjacent to the transport unit?

You can only place reinforcements in home cities with supply level 4 or higher. So German units can only be placed in Germany and Italian units in mainland Italy (not the islands, Albania or Libya). You need to trace a land connection to a primary supply source (Berlin for Germany and Rome for Italy).

By having the escorts adjacent to the transports you preven enemy naval units from targetting the transport (except CV's and air units who have an attack range of more than 1). But the easiest way to reinforce Libya from Italy is to sail the transport from port to port. Surface naval units can't attack units in port. Only 1 sub attack and 2 air attacks per port per turn is allowed. But if you want to transport units e. g. across the Atlantic it's good strategy to place escorts adjacent to the transports. You do the same about convoys.

Before you get many escorts you can e. g. place DD's in a triangle around a convoy. That means 3 DD's per convoy. This way you will
always be able to attack the sub with 2 DD's if it attacks the convoy. But the DD's can be vulnerable to sub attacks. So later in the game it's common to place a CV and convoy (or several transports in a group) inside a circle of escorts. This way the CV and convoy are protected from direct attacks. The CV will then have attack range to all subs going after the escorts.