Protagonists are usually the main characters of our plot and story, but they are rarely the secondary character. They are good guys, they have positive effects on the story, and they usually have an enemy, someone or something that doesn't like them, or a huge problem. To say the least they are the characters that are positive and come to save or help fix a problem. The character is never to be seen in a negative light ,unless their character undergoes change and becomes the antagonist.
A few examples - Superman, Spiderman, Itadori Yuuji, Cady Jane Heron,Sponge-bob,Woody Pride.
A great way to remember is the Protagonists start with Pro, which is a prefix that can be used to say that they are good at something. Antagonist are the opposite and have a bad or negative demeanor.
HOPE THIS HELPS GOOD LUCK.