As an ISP, let me chime in: No, not necessarily. Just avoid any form of vendor-lock in (eg: onepage, wix, ...). Given your question, I assume, you are not overly tech-savvy.
you are also fine running a cheap virtual host or virtual server. It's also OK, if you use the hosting-companies SQL-Server for your CMS (I suggest you do, so no hassle for you with patching, upgrades and security stuff). Important is, that you have means to 'dump' the stuff and move it somewhere else.
Point is: use your own (domain-) name, so u can move your emails and or content somewhere else, with a limited amount of hassle.
So: No vendor-specific stuff. They will prey on u, as they can guesstimate what a move will cost you, and calculate from there how to extract the maximum amount of money from you.
Hosting with a hosting-company is perfectly fine, as long as you don't use their special-sauce, which will run exactly only on their servers.
And if you are using CMSs - by the love of god, limit the amount of plugins. The ideal amount is 0, for that matter, and before you ask.