No. Certification is completely optional. I certainly did not need certification to get work with good companies (and bad companies too, for that matter). Some folks find that certification has been beneficial, but others found it has done nothing for them at all. My reaction is that we do shops to earn money, not to pay for a whole lot of 'services' of questionable merit.
As a shopper you will develop computer skills. There are things that will make this a whole lot easier for you. For example, an 'all-in-one' computer printer that can scan, fax, copy and print is a truly wonderful thing. A lot smaller 'footprint' in your computer area than a flatbed scanner, much less a flatbed scanner and a printer. These can often be found in the 'clearance' area of your local chain office supply place as they bring in new models. 300dpi is more than enough for this line of work and I would not bother with color. If you can pick up one that uses TONER instead of INK cartridges, your cost per toner cartridge will seem outrageously high until you realize that 1) they are often on really good sales and 2) you will go through a whole lot of ink cartridges in the same time it takes to go through one toner cartridge. You also can frequently pick up printers on eBay but there I would encourage a 'new in box' item.
There are software suggestions at [
www.mysteryshopforum.com] for free software tools. Keeping your machine up and running is essential to this work and I am in favor of FREE as opposed to paying for a whole lot of stuff. McAfee and similar subscription programs are ripped out of a machine as soon as I buy it because there are FREE programs that do as well, if not better and don't plague me with reminders to send money to upgrade or because my subscription is about to expire.
And it is not that you are 'thickly', it is just that you haven't needed to fend for yourself with a computer. Necessity is the mother of invention and you will find your skills growing rapidly doing this stuff. Just don't panic.