Should I start with an app or a webpage?

Hello All, I am a new startup entrepreuner, from a non technical background and have two questions 1. What is better? app or app/webpage or webpage as the initial entry? 2. Currently bootstrapping, but defnitely sure this is aan amzing venture benefiting seniors in the world, When should I start working and looking for pitching to investors ? ( I don't think I need much usercase, as I am a former physician who worked almost 2 decades in this field and the idea stems from it ) Thank you

I think the question is: Should I start with a native mobile app | web app/mobile web app or a content website (this one just offers information about the service or product, like a landing page).

I would recommend for you as a domain expert to determine first the type of users you are aiming to reach and what type of distribution channels (Mobile, Desktop, Web,etc) they use more. As well build a persona of the target user you want to solve pains , so you can determine the goals , needs and figure out what's the best experience you want to build for them with your product/service and what they really need to change in the actual process of their jobs to be done.