screen size is too large after freebsd install

[Joe]

Hello,

My name is Joe and I am totally new to FREEBSD.

I have spent over 2 days trying to install this software but no matter 
what I do the desktop size always ends up being too big.

If I click on alt + ctrl + - or + nothing happens. Tryed altering the 
xf86config file it won't let me.


Why is this so hard seriously its a pain.

Can anyone out there with a step by step guide on how to fix this help 
me please?


Thanks


Joe