i have one goldfish (female) in one goldfish bowl and i change its water at least twice a week. it has a red mark on its head (it looks like internal bleeding.. ) and i dont know what its from and if its something dangerous. please please help

Hi and welcome to the site. There is a ton of information here that will help you learn how to take care of your gf.

First I will give you the news of gf die in bowls. Bowls are not a proper enviornment for them. I know we all grew up with this thinking. But experts have proven that gf need 10-20 gals of water each. Fancy gf 10 gal and commons 20 gals.
This is because they produce lots of waste that build up toxins in the water that kill them. It would be like you living in a sewer. Not good.

So with this new information and education of gf and the water needs. ARe you able to upgrade to a tank that is proper for the fish?

IN the meantime I would recommend that you change the water 100% everyday until you can get a bigger tank, a filter and an airstone.
With these water changes you will need to use a water conditioner each time and temp match the water.

How are things going?