Yea quite fun last night even with the little argument in the 2nd game
I know you said you read the "Welcome to Dota, you suck!" guide but it's a pretty massive guide and a lot to digest in one sitting.
For example advice I gave last night is also in the guide:
"The final most important thing you can learn about laning, is PLEASE FOR THE LOVE OF GOD DO NOT AUTOATTACK THE CREEPS. There is a place where the creeps meet and beat on each other until they die. This is called the creep line. The creeps do a very exact amount of damage. Generally, if two waves of creeps fight endlessly on flat ground, THE CREEP LINE WILL NOT MOVE. If you start auto attacking or nuking the creeps, the creep line will be pushed closer to the enemy’s tower. When they enemy is closer to their tower, they are closer to being safe. It is so much more difficult to gank heroes when you can’t sneak behind them before initiating the gank. For this reason, DON’T AUTOATTACK THE CREEPS. Instead of auto attacking, right click all over the ground, run in circles until you are ready to last hit, spam the S key(stop) to animation cancel your hero(BEFORE he throws his attack). Just don’t auto attack."
It's important to remember if you are playing "support" you don't try and kill the enemy creep, as you want the carry to do this as he needs the gold reward. What you can do though which is still good practice for last hitting, is to try and kill our own creeps, which stops the enemy getting the gold reward and also gives the enemy less experience.
I have this command set in my Dota 2 config
dota_force_right_click_attack 1
^ This allows me to attack our own creeps when they are below 50% health, to try and deny them from the enemy.