First thing that platform should I choose? I think the most easy way to build a webshop is to use a CMS system. Systems are systems that are well-tested and extremely popular. And these systems are simple to customize and simple to use. I advise you to choose WordPress. Why? I'm a software developer, so I will use any CMS system easily, but my customers can't use most of the CMS systems. My experience is my clients can learn WordPress in a time and it can be used by them without my help. And you will see at the end of this article.
Documents can easily get lost if you don't have good protection on your website. A few of those files might be stored in your computer and easily replaceable, but what about the rest of them? Where will you get them out of again, if you lose the first time to them? Especially fix malware problem is very important. Often, long-term sites have a good deal of data and moved here have created a high number of documents. Recreating all of that would this page be a nightmare, and not something any business owner would like to do.
Protect your login credentials - Do not keep your login credentials where a hacker could locate them. Store them offsite, and even offline. Roboform is good for protecting them, too. Food for thought!
Keep your WordPress Setup to date - One of the simplest and most valuable tasks you can do yourself is to ensure that your WordPress installation is upgraded. WordPress provides a notice on your dashboard to you, so there's really no reason.
Now we are getting into things. Whenever you install WordPress, you have to edit the document config-sample.php and rename it to config.php. You need to install the database details there.
Don't use wp_ as a prefix for your own databases. That default is being eliminated by web hosting providers but if yours doesn't, fix wp_ to anything but that.