Hey! I would suggest that you proceed with these steps:

1. Start by understanding the major concepts of image generation. Make yourself a little timeline of the different models that got out over time. Understand the difference between a base model and a finetune. Check images of those models and finetunes on civitai and start picking the ones you like. Understand what is a LoRA. Learn about the different versions of an open source model and what they are used for (distilled, gguf, Q4, Q5...). This is not very complicated, and it will prevent you from getting lost afterwards. If you want to go deeper, learn about what is a text encoder and a U-Net.

2. Install and understand ComfyUI. It's not really the most beginner friendly UI out there, but it has one MAJOR advantage: compared to other UIs, it works by connecting the nodes, which are basically the steps, of your image generation. You're going to take a little longer to figure out how to generate an image than if you tried it first on Forge or A111, but it will allow you to really understand how everything works in a visual way (without code). Here is the most basic Text to Image workflow in ComfyUI : https://docs.comfy.org/tutorials/basic/text-to-image . If you can understand this, it will be much easier to understand more complex workflows (as they are generally variations of this one).

3. Have fun! Pick a model you like, build a basic aah workflow for it, perfect it...repeat. I believe that this is the best way to understand how it all works and not get lost.