Should i do the same weightlifting exercises everyday or change them up in order to gain muscle?

Work different areas: You should work different areas so that the muscle groups have time to rebuild. For instance one day do arms and shoulders, the next legs and back.

More infrequently.: Muscles need time to heal and recover from a weightlifting session, so exercising the same muscles every day will lead to overtraining and a lack of benefit. Train each muscle group once weekly, divide your body into five or six sections and weight train 20-30 minutes at a time. Give yourself one or two days of the week without weight training to aid recovery. Here, less is more.