When we start training in a gym, we always want to lift more weight to “get results faster”. This is a myth and a mistake that you should avoid since if you overload your body, the result will be a decrease in muscle mass or, in the worst scenario, an injury.
So if you're new to the gym, it's important to know how much weight to carry. Each person is unique, so any trainer must first assess your physical condition before suggesting that you carry a specific weight.

There is no "right weight"
Our body is a very complex dynamic system that is in the balance until it is exposed to stimuli that alter our state of homeostasis. This is what happens when we exercise: we apply an external stimulus with each exercise until the body's state of equilibrium is broken.
Depending on the applied load, our body begins to adapt, that is, we become stronger and more resistant. That said, there is no magic formula that tells you what the right weight is to promote this adaptation process. However, there is a relative effort that you can apply to ensure that your exercises are effective.

Self-regulation of exercises
When starting a set of an exercise, we must measure the effort we make to self-regulate during training. This is an empirical process, that is, it depends on each person.
Effort can be measured with a very simple strategy called chambered reps. The idea is that when you do a set of any exercise, you end the set when you feel like you could have done four more reps. Said in another way, you should choose a weight that allows you to get to the last rep feeling like you could do more.

This is the least effort you can put into a set if you want to get a proper stimulus in your training. When you have more experience exercising, you can reach muscular failure, that is, when you cannot do another repetition without neglecting the technique.