there is no set rule on how much or how long you should practice..Practice with in you confortable area...If it starts to get unconfortable then take a break...Dont worry your self if you dont get to practice one day..not everyone has all day to practice.
Another thing.....learn to READ music...its much better than tab
One more thing...Guitar takes alot of time and effort...it took me 1 year and somtihng before i was happy with what i was doing...seemed like forever before i started progressing