How to Buy a Computer
I generally recommend that you purchase Dell computers although their reliability is generally no better than other manufacturers. You can see reliability ratings for desktop computers here or for laptop computers. Additional information is also available. If you are shopping for a printer, you can see consumer reliability ratings here and business reliability ratings here. PCMag has an excellent article with lots of information about buying monitors.
All computers and monitors should be protected by a surge protector. This article offers ratings of various surge protectors.
You can learn about the differences between Windows 10 Home and Professional. Windows 10 comes in 32 bit and 64 bit versions. You can learn more about the differences between 32 bit and 64 bit. Windows 10S is described here.
Some computers are coming with Solid State Drives (SSD) rather than hard disk drives (HDD). An SSD is much faster than the old HDD, although the former are several times more expensive. You can read an article that compares the pros and cons of each type of drive. You can read about other highly rated SSDs. SSDs come in different form factors (shapes) and they come with different buses. All of this can make purchasing an SSD complicated, because you have to buy an SSD that fits in, and is able to work with your computer. You can read more about this complicated subject here here here or here. Here are directions that explain how you can install a SATA or M.2 SSD in your computer here. There is a lot of confusing nomenclature used when discussing SSD. This article explains most of the terms you will see.
You will want to get word processing software (and perhaps spreadsheet software) for your computer. If you want to buy Microsoft Office, the least expensive way to do that is to buy the MS Office Home and Student Edition, which is widely available at Office Depot, Microcenter, and Staples for $149, or even less when it is on sale, which is frequently. MS Office Home and Student edition is also available on some, but not all Dell computers. Home and Student edition contains Word, Excel, and PowerPoint. There are 2 other versions of MS Office known as Office 365 Home and Personal, which you can compare to the Home and Student version. Finally, you may wish to compare MS Office 365 with Office 2019.
Microsoft Office Online is a free version of Microsoft Office. As it's name implies, it includes free online versions of Word, Excel and PowerPoint. The online version is available here, and you can also read a detailed review of the product. Microsoft Office is also available for your iPad, iPhone, and Android phone, in addition to the Desktop and online versions. Each version has different features which are described here.
You can also get a product that is very comparable to MS Office called Open Office here. It is free of charge and has received excellent reviews. Other alternatives to MS Office are Google Docs and Libre Office. You can read a comparison of these products.
If you need additional email software, Thunderbird is an excellent choice and it is free.