I've had two railroads with different names. My first was in the Denver area, we lived on Green Mountain (in Denver is was usually brown). At that time I had two loops on different levels connectected by a cog railway. The upper loop was used for LGB European trains and the lower loop was for Colorado Narrow gauge. The name of the railroad was the Grun Mountain und Western, a mixture of German and English to match the trains I was running. The cog railroad became the Trans Atlantic Express.
In Virginia I have 1 loop and generally run North American style, both narrow gauge and standard gauge. We live near a lake called Clear Lake. The name of the railroad is CLEAR LAKE LUMBER COMPANY. Occasionally I will build a kit or get some unlettered cars. I have had Stan Cedarleaf, one of the sponcers here on MLS, nmake some decals for the CLLCo.
As others have said give it time and something will come to you. You can always change it and if you have lettered some cars for an older name, they will add to your memories. Here are a couple of CLLCo cars.
A Sheridan box car kit,
A "Phil's Narrow Gauge" reefer kit.
Again welcome to the hobby, if you can find and join a local garden railway club. If you let us know where you live, I'm sure that someone will be able to put you in touch with a local group.