the 5x5 is a 'strength' program, per say, it gradually allows you to add weight in very small increments thus increasing your strength gradually thereby adding muscle mass. you will run into issues if you have never squatted though, i noticed you deadlifted once you stated? well,l89 get your form down on the big 3 and make dam sure you are not maxing or heaving, strict form is the rule now. read the forums here, check out the member vids, look for squats deads and benching, im not sure you will be ready to jump into this on monday seeing you have neglected 2/3 of the exercises needed to properly execute the program. give yourself a couple weeks to get the form down, i would still go 3 days a week to get the feel, then start your journey.