WHEN DO I HAVE TO FILE?

Ive recently started a small business and I'm at the point where I have to get my resellers license so I can really get started. Ive been doing some research and I'm seeing that once I get this license I will immediately have to start reporting my taxes even if I haven't sold anything yet. With that being said, how do I know that dated that I have to file? I saw somewhere that since my business is LLC/sole proprietorship I can report my business tax with my personal taxes during normal tax season, but Ive also seem some say that they got their license and started to get penalty fees because they missed several dates that they needed to file on throughout the year. As far as reporting my taxes, which scenario would apply to my business?