Now it is time to start devising your initial workout. I think the best way to begin is nice and easy. You want to establish a foundation of strength and control to set yourself up for the Max-OT (Maximum Overload Training) system. Max-OT is the training approach you will move into in the weeks to come.
For the first 3 weeks, your initial goal should be to familiarize yourself with the equipment and the exercises. Too much too fast is not an intelligent way to begin. You are not going to start by attempting your maximal bench press. It is not a contest to see how much you can lift, it is a phase of your plan designed to give you a foundation to build upon.
When structuring any workout schedule it is important to remember that weight training is the stimulus for muscle growth. To respond to the stimulus you need to let the muscle recover. This means if you want bigger biceps, the worst thing you could do is train them every day. This would be counter productive to your goal because you are never letting your muscles recover. We call this over training. With this in mind, you can see that it is important to have a structure to your workouts and not just wander around doing exercises with no real rhyme or reason.
You are going to start by working out 3 days per week and training each muscle group 1 time per week. This will ensure that you are getting maximal recovery to effectively respond to the stimulus. You will begin with higher repetitions per exercise and lighter weights. This will help you get accustomed to the exercises and get familiar with the feel of each muscle as it is worked through a range of motion. It will also give your tendons and ligaments a chance to get ready for increased overload in the future weeks. In addition, an intelligent start will enable you to avoid extreme soreness.
There is no advantage in killing yourself the first time in the gym. You will have plenty of time to increase the intensity as we move into all out Max-OT training, but for now, focus on establishing a foundation.