theming – Joomla convert seeking to build a Bootstrap 5 based theme for Drupal. Please Advise

I have been using Joomla for years and also made few themes for it. But now since 3.X is long in the tooth and J4 is not stable enough (esp for Chromium based browsers) yet I have decided to convert to Drupal.

I have to say I am so far blown away how awesome Drupal is!

Now, I am building a simple shop website for my software and games. I would like the website to have esthetics of with possibly implementing a nav menu similar to that on

My idea is to build a theme for it from scratch so I can learn about theming in Drupal. I would like it to be as minimal and simple as possible as a starting point, just to be able to drive my shop website and then build upon the theme in the future as I gain more experience.

Now, here’s the problem. I don’t really know where to start! There’s a lot of documentation and themes around but it’s really hard for me to find a starting point in Drupal. I mean, what would be the most current approach and best practice here?

I think I want to build a base theme. The reason being is that I want the theme to carry over to future versions as smoothly as possible without too many dependencies? So for example I don’t think I want to base a theme on Classy or Stable (or am I wrong?).

My objectives:

  1. A responsive theme built with Bootstrap 5.
  2. Minimalistic, no bloat, simple and basic.
  3. A starting point at first and then something I can improve later on.
  4. I would like to make the theme within a month of time.
  5. The theme is a custom theme for my website, I am not planning to distribute it, sell, nor need to have it work with other websites. Ergo, I would be the only user of it (as this is part of my learning process) so I don’t need it to have tons of customization options available and it doesn’t need much flexibility in terms of environment.
  6. I would like to build most of the code myself so I know the template inside out. That is except the code I would need to make BS5 work smoothly with Drupal 9 as that is probably something standardized.

My questions:

  • A. Should I start with a Base theme like Fusion?
  • B. Should I start with a starter theme like Bare Bones?
  • C. Should I start with a theme that already has Bootstrap 4 implemented (as I can’t find any basic ones with BS5 yet) and then convert that to BS5?
  • D. Is my idea of making a base theme sensible, or should I rather use Classy as base theme and build a BS5 theme on top of that?
  • E. Should I start with something like the Radix theme?
  • F. Should I start with the Bootstrap 5 admin theme and just
    convert that to front end theme?

I hope this makes sense. I am really a bit confused here because it seems there’s so many ways to skin the cat and I would really want to know which one would be the most efficient one for the goals I have.

Thanks in advance for any feedback!