If I want to build an MVP, would you advise me to go for a PHP clone script or a WordPress clone theme? I know I have to develop something from scratch eventually, but this is for demo use in the initial stages. I am not a developer.
Well this totally depends what your MVP is? What's the functionality? I'd suggest something like http://www.squarespace.com/ our designers with very little technical knowledge have had great success with this.
Another option if it's just for demos/feedback is to use something like http://www.invisionapp.com/ for rapid prototyping.
I'm a bit biased (I absolutely love WordPress) but I would recommend WordPress for the following reasons:
1. With Wordpress there is way more documentation and support than your typical PHP script would have.
2. There are tons of plugins that will allow you to add extra functionality if needed. With your php script you'd probably need to just write that yourself.
3. WordPress includes a full content management system and learning that system will be a useful, long-term skill. Learning to code would also be useful, but if you have no idea where you're starting, getting to the finish line will be a daunting task.
If it were me, I'd go the WordPress route, but as this is an MVP, either would probably work. Hopefully this is helpful. :)
If this is purely a proof of concept, I'd go with WordPress. So much of what you'd need in an app platform is already there, plugins for anything & everything are plentiful, and it's incredibly easy to add any necessary custom functionality in via PHP. Depending on what you are building, you might not even need to build from scratch if it works.
Plugins like Advanced Custom Fields Pro, Gravity Forms, Custom Post Type UI, WooCommerce, and MemberPress might come in handy.