Texas

I am looking for information on selling cottage food in Texas. I’ve done quite a bit of research so there are only a few things I still need clarification on.

I know you cannot sell online, can you advertise online such as a facebook/instagram advertising what you have for sale or where you will be selling?

Would someone need to file a “doing business as” in order to sell their cottage foods under a business name?

How are income taxes or sales tax on any food items from cottage food sales handled?

Would a store bought can of cake icing be safe to put on cakes for sale as cottage food items?

Thanks!