I suggest that you start with "baby steps." Take on or maybe two different shops. After each, make detailed notes in your car. You may discover that just repeating key points out loud to yourself, as you walk back to the car fixes them in your mind. (If you hear someone walking past your who is intoning, "male, 6' tall, short red hair and beard, wire rimmed glasses," you have encountered another shopper. lol) As a beginner, you may find that you want to print out the survey and use it to check off items of importance immediately after getting back to the car. In the long run, this gets too pricey, so some of use make up short checklists that reflect key survey questions and do those right after the shop. Just be SURE that all paperwork is totally out of sight in your car.
Go home and submit your reports. Submit the one(s) with the shortest deadline first, of course.
By taking only one shop of a type (fast food or bank, or retail) to start, you won't commit yourself to doing several of one kind and then discover that it is just the sort that you hate! Also, please take a deep breath and remember that the first time that any of us, veterans included, does a new shop, we are a bit nervous and the survey takes much longer to complete that it will when we do the second or third survey like it.
If you want to enter reports into a laptop while on the road, I suggest that you find a coffee shop or fast food place with free wifi and sign on there to enter reports.
Based in MD, near DC
Shopping from the Carolinas to New York
Have video cam; will travel
Poor customer service? Don't get mad; get video.