Weight lifting is not easy when you have never done it before. There are certain things you need to know and do properly or you will get hurt in the process. 5-10 minutes before you start your workout, stretch and do a jog and some form of cardio, this will get your blood flowing and stretch your muscles before you lift. You should never take a break to eat, at all. That will lose your motivation to keep going, your goal should be to keep going until you physically can not lift anymore. Be very very careful with your joints, never lock your knees, elbows or shoulders because then they will break or be severely injured. Also have steady breathing, because you obviously don’t want to breathe heavily through the entire workout. Drink a sip of water between each set. Don’t put a lot of pressure on your back, you are not really suppose to use your back for anything when lifting, you will strain it or worse. Some soreness especially when you first start is normal and good, it means your muscles are growing. You will not see improvements or results from a good few weeks or couple months so you need to stay consistent with your workout. And take 1 or 2 rest days, they will not hurt and it is good to rest your body.