Need some help with PHP & mySQL

I think you're not fully embracing the lean startup methodology. Is your SaaS handling some operations that are a matter of life and death or critical mission thing for an organization? if the answer is No start with simplest option and do a soft launch and invite some carefully selected (50) beta testers. Get the service going and gather feedback as much as possible. Then when you're at version 1.5 or 2.0 you'd know the problem you're solving a lot better. Slavi, Orbisius & qSandbox

I would probably look at a course on udemy for that specific case https://www.udemy.com/getting-started-with-php-programming/?dtcode=MzjhAx31ASRH

Be careful when simply wrapping things into a mobile app. This can backfire on you and you could be presented with some very harsh edge cases. PHP isn't going to be encapsulated so much as the HTML/CSS/JavaScript. So keep in mind your mobile application could likely be in a position of requiring an online connection to work (because it must interface with your existing hosted WordPress site). This could also mean your hosting solution needs to be evaluated to ensure you can handle any increased traffic (and those traffic patterns could be different when coming from a mobile app that perhaps loads things the user doesn't see right away, accesses content that may not be cached, etc.). You want to ensure your server doesn't go down because then your mobile app would be "down" as well. That said... Things like Phonegap (web views) are a wonderful idea for utility apps because the performance is good enough for those (and hey even some games) and they end up being easily ported across many mobile operating systems. I would look into Phonegap, Appgyver (a new and totally awesome one because parts of it will utilize the native OS and your app will feel more responsive), Appcelerator Titanium, and perhaps even the new Famo.us one. Also take a look at the Ionic Framework for some further ideas about mobile UI and what you can do with these web view style apps.

Digital marketing is broad but can be plainly described as: the creation, distribution of and engagement with, relationship or brand building content in an electronic format.

Hi, I have been a PHP developer for 13 years and have experience building enterprise applications. What framework are you using? Most PHP frameworks have a built in authentication and authorization mechanism. For example, Yii has a builtin RBAC system that allow you to define a hierarchical permission system. If you're not using a framework or you just want to implement your own system for whatever reason then you can utilize Object Oriented Design and implement a Base controller (if MVC) that checks the permission for each request. That won't use a lot of if statements. Probably need more info, to give definitive guidance. Hope that helps.