If you're in the stream of commerce in any manner whatsoever, getting your product registered with the proper marks is very important. The marks also create an asset for your new company. One of my colleagues in my firm's DC office handles this sort of thing regularly and can be of assistance, as may other AVVO members on line.
The foregoing is not legal advice nor is it in any manner whatsoever meant to create or impute an attorney/client relationship.
You should consult your own trademark attorney to get specific advice for your particular situation.
Generally though, for federal trademark registration, "commerce" means commerce that Congress can regulate, like interstate commerce or U.S. international commerce. "Use in commerce" must be a bona fide use of the mark in the ordinary course of trade for that item, which is different for various industries and various trade situations. One sale could be enough for certain industries / items, and not for others.
Regardless of whether your specific situation is enough to qualify as use in commerce (right now) for federal registrations purposes, you can still consider filing an Intent to Use application. Ask your trademark attorney whether this might be right for you.
Best of Luck!
Legal disclaimer: This answer is not legal advice, but is for informational purposes only. My answer to your question does not create an attorney-client relationship between us. Please contact a licensed attorney in your area for competent legal advice.
You're operating under a misconception. Trademark rights arise AUTOMATICALLY whenever a person uses a protectable mark to brand a product or service that is then sold in commerce. ONE sale suffices. More sales are better because the more sales the "stronger" the mark ["stronger" meaning the greater ability to stop others from using the same or a similar mark and, likely, within a larger geographic area]. So if any of those gas stations have sold any of your product to consumers then you've got trademark rights in your mark. This assumes, of course, that you are, in fact, the first to use that mark or one confusingly similar to brand that product or one related.
If you want to REGISTER those trademark rights then you need to first determine if your mark is being used in "interstate" or solely "intrastate" commerce. If the former you can register your mark with the federal trademark office. If the latter then you can register your mark with your state's trademark office. You should discuss this matter with your own trademark attorney. A federal trademark registration is of more benefit and because it only takes a little planning and effort to convert an intrastate-only use into an interstate use it makes sense to chat with your own attorney about how to do that.
The above is general information ONLY and is not legal advice, does not form an attorney-client relationship, and should NOT be relied upon to take or refrain from taking any action. I am not your attorney. You should seek the advice of competent counsel before taking any action related to your inquiry.
It is very likely that you have done enough. Get a lawyer..do a trademark search and file a trademark application with the USPTO if the search is clear...ASAP. "Interstate Use" is required. That is interpreted loosely and if it can be shown that travelers from other states occasionally visit any of these stations you have satisfied the interstate use requirement.