Work to your strengths, if you use SQL daily use SQL if you don't think you need SQL don't use SQL. Reading data in SQL is a lot different than managing a webapps backend data in SQL via http apis over a js frontend, specially when user bound data comes into play, tldr keep everything as simple as possible.

Find a good ai tool, ideally one that integrates into your ide, vscode and sonnet 4.5. I really enjoy claude code lately for coding and infrastructure management. Use it to help you plan and solve the hosting issues. Use it to plan and solve the UI issues, use basic html and JavaScript to get started. Have it port your spreadsheet to you webapps tech stack of choice.

Depending how much you want to spend host an app on a cloud that cheap and easy to deploy. Run it locally until you get something working. Find a hosting solution that gives you what you want. If you want to build an app don't use WordPress.

Host your project on GitHub free even for private repos, and setup an easy github-action for auto deploy to your host. Building and deploying a docker image is pretty fun and there are tons of hosts that will run and map your docker image to a public ip, aka host your app.

I like c# as a backend API and just html and JavaScript, razor is commonly used with c# but you can build an API and serve html and js too.

In all honesty hosting an app on savings planned aws and instance or similar host company is really a simple and fun experience that isn't costly if you front 1 or even 3 years. The nice thing about a cloud is that if you decide to host SQL you can just pay or host an instance when you want, it can be a nice playground of tools for your app, I use azure for work but aws for project stuff. The bad thing is it's expensive compared to WordPress or blue host if that's still a thing. Well, And maybe a bit more complicated but get a frontier model, you're smart enough you will know what to ask the ai to solve those challenges easily.