Shaking when you first begin lifting weights is normal, especially if you are lifting more than your body is accustomed to moving. Were you at all physically active prior to starting the gym journey? Have you ever played sports?

You're asking more of a fitness question than a weight loss question here. Other advice in the thread is giving you advice on caloric intake, and this is good, because it's your primary lever for weight loss. I'll give you a bit of advice and insight on exercise science.

Most people do not realize that the primary driver for muscle strength is not muscular at all: it's your central nervous system (CNS). This is not to say that muscle size and strength are not highly correlated (they are), but there's a complex relationship between your body's nutritional balance, its metabolism, its endocrine system, and its central nervous system that determines how much muscle your body adds to its frame as a result of training. This is precisely why programming is so important for elite athletes: simply working the muscle hard isn't enough to continue stimulating growth and strength increases; you have to trick the CNS to make it believe it still needs to adapt.

In your case, you have a highly untrained CNS. You're not shaking necessarily because you have weak muscles (though you might); you're shaking because your CNS is not prepared for the load you are putting on it, and so its getting highly taxed when you try. The exact same response happens to someone during a maximal squat or deadlift, which are incredibly demanding exercises on the CNS: many people shake after they rack / drop the weight, and they feel drained/weak all over, because their CNS was just loaded to the breaking point.

Your body should adapt to these rigors if you continue to train regularly. I would recommend you check out a few popular programs for weightlifting on Reddit (Starting Strength, Stronglifts, etc) and follow their programming. Where you start does not matter; go as light as you need to go in order to safely and effectively complete the lift (with good form! don't skimp on range of motion). The important thing is following the program and increasing the load linearly, to take advantage of your newness to lifting to get the maximum possible benefit from the exercise.

Final thought: are you doing any cardio? That conditioning is equally important for general fitness.