I have a small bump more like the size of a piece in the left inner side of my anaol! How do I know if it's a pimple or a hemorrhoid or something else?"

I have a small bump more like the size of a piece in the left inner side of my anaol! How do I know if it's a pimple or a hemorrhoid or something else?"

In your anus? The size of a what? ('piece' isn't much help.)
It could be either a pimple or a hemorrhoid or cyst, such as around an ingrown hair.
They are very common, especially as we get older, or have babies.
You can soak in a tub if you wish, or just wait.
Hemorrhoids of course usually increase rather than decrease, but there is easy outpatient surgery if they get too big or bleed too much.