Most people who experienced side effects from the vaccines had mild symptoms such as a sore arm, fatigue, headache, muscle aches, and fever. Side effects usually go away after a day or two, and are a sign that your immune system is working and preparing itself to fight the coronavirus in case you are exposed to it.
As more people get the vaccine, there may be some very rare serious side effects (1 in a million.)
Many people have no side effects from the vaccine at all.
It is always important to balance the potential side effects of the vaccine with the risks of not getting the vaccine and maybe getting COVID. You can talk more with your medical provider about the risks and benefits for you.