Is it okay to start a company based on an idea that has already been taken?
YES.
Rarely will you have an idea that is so original that no one else has done it.
If you are lucky, no one in your area has done it (or done it WELL) yet. Ideally, you would choose a business where the market is not saturated with others who offer what you are considering.
If it is a totally new idea, it has “blue ocean” potential which means no competing sharks, so that is great.
