Who do you go to if you want to see if a business name you want to use is available?
In my state it is the secretary of state’s office. On that web site you will likely find a link to business services or similar. In that area look for name search, name registration, etc etc
Our Superior Court Clerk registers trade names for the county. We can go into their books . . . same roon as real estate deeds and plats . . . and look them up.
Locally we need to call the secretary of state to find out but how do you find out nationally?
Just googling it will often provide info as to whether or not it’s being used. Of course, it’s no guarantee.
Go to the uspto website and do a search to see if it’s been trademarked (or look for similar, as any attempt to register a similar name trademark will most likely be rejected for "likelihood of confusion with existing mark.
The actual trademark process can be done online and all told, takes about 9-12 mos, start to finish. I think it costs about $300 or so.