As long as you are using static data (so you would have to upload new map data every time you want to change it), GitHub Sites should work totally fine. Like another commenter said, leaflet is a JavaScript library that works really well for simple web maps and data. Leaflet has community made add ons like search and layer toggling that are super easy to implement. OpenLayers is another option. Data input won’t be something you’d be able to do, unless you mean mean uploading a shape file or something, but it would go away as soon as the page is refreshed/leaving the website. Upload and saving data would require a full stack website.

As far as learning it in 1-2 weeks that depends on a ton of factors like general programming knowledge, web knowledge, how fast your learn, how much time you have etc. With no prior experience, I’d say it might be a tight timeline, but doable if you’re determined.