Need help figuring out what language to use

So I am looking to found a SaaS company, to address a hole in a niche market with a HUGE gap. My issue is figuring out what language to use, as I know nothing about programming languages, rather I know the niche and the needs to solve the problems. So I am looking for some help. Here is what I am trying to do: - custom form builder, so the end user would have drag/drop capabilities, but also responsive questions(answering one way, as set by the end user, allows another question or a trigger such as requiring an upload). The rest of the usage is normal for a form/audit app, but so many lack the responsive question trigger - dashboard widgets: so the end user would have a dashboard where they could choose various widgets of data, such as action items, open audits, capa tracking. These widgets could be simple numbers, or charts depending on how the user sets them. - user levels: ability to set different levels of use, a base user would have access to some features, where as others would have more access, before getting to full admin level. - ability to track compliance: so for example, let’s say you wanted to track contracts, you could enter basic info, then upload, then assign a deadline(due by) date for when that contract must be cancelled/renewed. That sort of thing. Also same functionality for action items, corrective actions and such. - open user access: so here is where many miss out. I would like the ability to set forms public, where a simple single digit code gets access to just the forms, as opposed to full backend access, so I could provide all employees with a simple code(or use employee ID), and they could login and just have the audits available to their level. - add assets: so I could input company equipment, then add that equipment into forms, select it, build a time based audit against it.

It would mostly be a forms app just with lots of functionality to have company built ones and also customized user ones.

At first this would be a website but obviously I would like to add it as app for android and iPhone as it grows(not sure how much that would effect the language).

Any suggestion for the language that would be best is most appreciated. I apologize in advance for my clear lack of knowledge on the language and such, so if anyone has any clarifying questions, I’m here. And I deeply appreciate any help anyone offers, as I would love to get this project going.