I came to offer advice on your first bullet point. Definitely look into the <label> element. This will let you click on the text associated with the button. Not knocking you here (as this is your first web app!) but I am shocked by the number of large websites that do not do this properly. Drives me bonkers.

You can use it one of two ways. Wrap the text and radio/checkbox button in the <label> tag such as :

  <label><input type="checkbox"> Medium</label>

Or using the for/id attributes as follows:

  <label for="boy">Boy</label>
  <input type="checkbox" name="gender" id="boy">

  <label for="girl">Girl</label>
  <input type="checkbox" name="gender" id="girl">

Excellent first app! I'm sure you've learned a lot about building it. That would actually really interest me, a blog post perhaps detailing all of the things that you learned while building it.