Young children can have a hard time containing their emotion or affect. They are in the process of learning to self-regulate but they are not fully there yet. So, at times it comes out or bubbles over like a volcano. It usually starts out as an emotional override as they are learning how to deal with or express emotions properly and in a healthy manner to get the desired results. It can transition into a manipulative tool if not handled properly. This is typical and part of a normal and typical part of development.
Going in with mindset will help you maintain calm and control when dealing with the tantrum. Maintain your calm and know that the child is trying to communicate and its not about you. Keeping in control of your thoughts and emotions help model calmly communicating. It gives them an example of how to get needs met calmly. Using your own cool just exacerbate. Also- do not pay them off with what they are throwing the tantrum about. Kneeling down, looking them in the, and addressing them with a calm voice can help defuse the situations. Removing the child from the situation and talking calmly outside of the scenario until they calm down will help reinforce that the tantrum is not a proper way to get the need met. For example, if the child is throwing a fit at the store. Abandon the cart and leave. Maybe go sit in the car and talk to the child about not being able to act that way, especially if it is over getting something like a toy or treat. Do not give in to that demand to pacify.
That is where the child will learn that tantrums will work to get the need met and it will turn into a manipulation tool. It is doable and this too shall pass. You got this!