need info please

[shell45]

Hi I am new to this so here goes, I have been using weights at the gym and just trying to change my routine, there is so much info out there I am confused, I need to know what to work on in a work out I go 3 -4 times a week, so do I work on shoulders, back & chest, one day and biceps and triceps another day, also need exercises for abs not very good at these. thanks