can someone please explain

the structure of multiplayer in game studio?

I've tried running through the tutorials and they work fine. but when i want to code something, its incredibly frustrating!!
variables just DONT send?
i've tried sending skills of entities to each other, doesnt seem to work. I've tried send var, send data, etc. and it seems to randomly decide to work when it feels like it.

My game's structure is:
the server creates 4 vehicle entites, that are arrays. They each contain 2 of the same vehicle, but are owned by player 1 and player 2 respectively.

The client connects, and should send the request to the server, to open up the vehicle selection screen... but it doesnt. I've tried reworking/restructuring the code so many times and its very frustrating.

Should i be doing this:
server creates all vehicles
client connects and sends WSAD movement to the server
server moves vehicle

OR
server creates his own vehicle
each connecting client creates their own vehicle
all collisions and such are handled on each machine

it really depends.. umm..
i'd go with:

server creates his own vehicle
each connecting client creates their own vehicle
all collisions and such are handled on each machine

since its not like an fps where you need to worry about cheaters much, what metwork system are you using? the default?

I agree with Darkinferno. Have you seen the multiplayer tutorials on AUM. They are very easy to understand and provide a good basic multiplayer script.

You could also give ANet a try, I think it's easier to understand and it has a great tutorial: www.anet-plugin.com

Look into the "Simple 3D Chat" tutorial, this should give you a good start into multiplayer.