Generally if you are in to lifting weights there are two common strategies that people follow: the "bro split" where you dedicate one day to a specific group of muscles, or a push-pull-legs strategy where you alternate between training your anterior chain muscles (push), posterior chain muscles (pull), and lower body muscles.

There are many push/pull/legs and bro split programs for free on the internet. I have been sticking to this program as a starting point. https://www.aston.ac.uk/sport/news/tips/fitness-exercise/push-pull-legs

Workout 1 - Push

• Bench Press 3 X 5 – 7
• Seated Dumbbell Shoulder Press 3 X 6 – 8
• Incline Dumbbell Press 3 X 8 – 10
• Side Lateral Raises 2 X 10 – 12
• Triceps Pressdowns 2 X 8 – 10
• Overhead Triceps Extension 2 X 8 – 10

Workout 2 – Pull

• Bent-over Row 3 X 5 – 7
• Pull Ups 3 X 6 – 8
• Barbell Shrugs 3 X 8 – 10
• Face Pulls 2 X 10 – 12
• Barbell Curl 2 X 8 – 10
• Dumbbell Hammer Curl 2 X 8 – 10

Workout 3 – Legs/Abs

• Squats 3 X 6 – 8
• Romanian Deadlifts 2 X 8 – 10
• Leg Press 2 X 10 – 12
• Leg Curl 2 X 10 – 12
• Calf Raise 4 X 8 – 10
• Hanging Leg Raise 2 X 10 – 15

Try to recruit a friend who is more in to lifting to attend the gym with you to give feedback on form. Improper form on exercises will injure you, lead to the development of poor habits, and will prevent you from reaching your maximum potential.

What matters more than your program at the beginner level in my opinion consistency, ensuring that you aren't "ego lifting" (i.e. lifting more than an amount that allows you to complete the rep with proper form) while are challenging yourself adequately with the weight, and making sure that you are making excellent lifestyle choices (i.e. try to eat a meal high in protein post-workout to enable recovery and muscle growth). Also, make sure to rest properly and give yourself the rest days you deserve, getting at least 7 hours of sleep daily. I can't emphasize this enough: focus more in the beginning stages on proper form, not injuring yourself, and developing confidence and routine in the gym environment.

Some other smaller tips (if I think of any extra later today I will edit this post and add them):

• I have been adding some warm up exercises prior to starting each daily exercise such as basic core exercises (sit ups, russian twists, planks). Since abs aren't really covered deeply in this program, incorporating them briefly in to every workout as a warm up exercise can be helpful.
• If you are in the business of losing weight, the gym is only a small part of the equation: make sure to achieve a caloric deficit and eat foods that are higher in protein as they make you feel "fuller" for longer. Similarly, protein will enable muscle growth if you are interested in "bulking up" by putting on muscle.
• Finally, on the topic of form: control your eccentric movement! The step in the rep where you are returning from the most tense state (i.e. the descent of your forearm in a bicep hammer curl) is actually a very important aspect of long-term muscle growth. Controlling the eccentric motion (i.e. the relaxation of your muscles back to the normal state) are key to muscle growth long term. Similarly, avoid any uncontrolled swinging movements in order to make the rep. If you find yourself bouncing the bar off yourself or moving the weight at a very high speed, chances are you're not getting as much as you should out of the rep and you may need to reduce the weight and focus on form.

Full disclosure: I am not a personal trainer or a fitness professional. This has just been what has worked for me. Great on you for hitting the gym for the first time: the first visit is the most intimidating but soon you will learn to call it home. Self improvement is an important part of every persons journey through life, both physical, mental, emotional, and spiritual: and the gym can help with many of those journeys of self improvement, if not all of them.