Of course, when you pick up a 3rd party product, there's always a very small risk that one day down the line that product might have support dropped for it, and that may or may not impact the systems you use for your business; however that's something which every business faces these days, so it's no big deal.
(Well, of course it's a big deal if it happens, but it's a risk which you can hopefully manage as part of your overall business strategy by keeping a fallback strategy)
On the other hand I'd say there's far more risk associated with starting a new project by building everything yourself from scratch. The risks are that you could end up with a product which is unstable, insecure, buggy, etc; and you'll have no support to turn to when something goes wrong - and if your business suffers as a result, you will have noone and nowhere to turn to.
If you're starting a business without having much tech knowledge yourself, then I would think the smartest thing to do would be to spend time researching the kinds of products and services out there which are within your budget, and already widely used by many other businesses in a similar situation to you - chances are you'll have plenty on your plate already without having to worry about building the web functionality from scratch too.