I've learned a lot from lawnsite. Tons of info on here. However, certain sections of the site require thick skin. One piece of advice is to not get too offended about what someone might say, regardless if you think they are just being negative to be negative. I made that mistake a few times early on until I figured the site out. After all, this is the public, there's all kinds of people out there.
If you are set on GN Services as your name, here's what I would do:
Do you have a color scheme picked out?
I would get a front license plate for your truck(s) that simply says "GN" on it, unless your state requires you to have an actual license plate on the front (some do). License plates are hard to read, so the simpler the better.
I would work on the GN in general. This is going to be your logo, your signature. You want people to be able to see the GN and instantly know who it is. In other words, the GN needs to stand out. If you do yard signs in the future, the ones that are required for lawn treatments (roughly 8"x8") emphasize the GN. Once again, they are small and hard to read, you want to get the point across very quickly so just a glimpse catches the point.
I would add color to the trailer. Two ways to do this. Blow up the GN to a much larger size and add a color to it, not just black. Or, make the back ground a color and do white lettering on top of that, or a light color for the lettering that is easily readable. This will make it "pop."
There's technically two options when getting your trucks and trailers logo'd up and that is vinyl or wrapped. Wrapped is printed, vinyl is just vinyl. We wanted a full blown wrap at first but were talked out of it from our sign place. They said since it is printed it will not last as long as vinyl, not NEAR as long. They fade fairly quickly, I was told within 2-5 years, and they are expensive, so you will be doing it again in a relatively short amount of time. And if someone side swipes you then you have to get the entire side of that vehicle or trailer redone, whereas vinyl is much easier to replace. Full wraps I would estimate for that trailer, maybe $2500-3500. Wraps look awesome, just a lot more to consider.