If you are interest in operating a bus that carries more than 14 passengers, you are goig to need a CDL license. In order to get this CDL license, you will need to pass some CDL practice tests before you take the real general knowledge test for cdl. You can find free cdl practice tests, so that you can get an idea of what the cdl test questions will be like. Once you past the CDL test, you'll be ready to get your CDL license and look into CDL jobs
If you are very lucky, you may be able to find free CDL training, and if you are EXTREMELY lucky you will be able to find paid CDL training. Some companies offer Company paid CDL training and if you find a company like that, jump at the opportunity. Worst case scenario, you get the paid CDL training, you past the CDL practice tests and then the real CDL test, you get the CDL license, and if you don't like the job, you can find another one with you shiny new CDL license! Always provide a professional level of advanced notice before quitting any job though, especially one that requires a CDL license, because you may find it difficult to get other CDL jobs if you get blacklisted. Besides, its just the respectable thing to do!