How Do You Find Cheap Fuel? Which apps and sites do you use?

Not sure about the fuel card but as far as if it will have space for you to pull in and get out. I am a newer driver and my first job was pulling tomatoes with doubles. And driving up and down I-5 which I was pretty unfamiliar with. I did not know any of the stops along the way and with the double trailers that are pretty impossible to back up if you get your self down the wrong street etc. If I wanted to take a coffee break I would just use google maps sat view to find the nearest food or gas stop and then just zoom in to get an overhead view of the facility to see if it looks like it had easy access and plenty of space to be able to turn around and get back out. Came in handy, a few places had decent areas to park my truck that I never would have noticed or been able to see even if driving right past the place. Hell, google maps sat view even got me out of a situation where I ended up on a narrow farm road and found myself dead ended at a canal. (These farm roads, you can not turn around with a trailer connected. You drop your trailer, do a 3 point turn and pick up the fresh trailer pointing the way you came. After I got to the field Dispatch told me to hook back up and continue on to another field as the harvester broke down. I could not go out the way I came in so decided to go straight and take the first dirt road left that would take me back to the main road but found a canal between me and the road.) I was able to find on the sat view that I could take a right along the canal (a tractor path) and find a crossing a mile or so down. This stuff does not show up on regular maps and without the sat view I would not know about the crossing and not dare going along the canal and get maybe get my self deeper down a dead end and would have had to walk a mile back and have a filed tractor help me out.
As for the gas station, Sat view will show you the layout, you can use street view to see if it looks like a place you can fill up (fit under the any obstructions) and there is usually a phone number for the business on google maps where you just click the phone icon to call you can call to ask if they take your card. Maps also includes business hours if they are currently open or not.

For fuel prices, I like Gas Buddy as it is simple and usually very up to date as users will update with current prices, usually from that day.