Should I start a small business as a LLC or DBA?

LLC and DBA really have nothing to do with each other.  The first is a structure of business operations by which the business is owned and operated by an entity, not you personally, and you own the entity.  Its principal advantage is that the individual owners of the llc are not generally personally responsible for the llc's obligations.  Because of this, many with whom the llc does business (i.e. landlurds, suppliers, etc.) may require guarantees from the individual owners before they will do busines with the llc.  The principal disadvantage is the extra taxation and costs of operation.  "DBA" simply means "doing busness as", and while it requires some registration and fees, does not affect the structure of the business.  An LLC can operate a business as a d/b/a.  For example, XYZ LLC. can operate a restaurant doing business as "Tony's House of Tacos."  Using a d/b/a has nothing to do with avoiding personal lliability, however.  If an individual operated a business under his/her own name or under a d/b/a, he/she would still be personally liable for the business's obligations.