Install the fish shell, it makes using the terminal waaay easier, out of the box.
Not a good idea if the goal is to learn more about Linux. Fish is not compatible to and is different to Bash in some ways, that it would be hard once not using Fish. Also getting help or sharing scripts with others will be problematic, when having a problem and researching it. For someone coming in to Linux and wanting to learn about it, I highly recommend to learn about Bash first and use it at least for months before even thinking about a custom shell. I used Fish too (and I miss some features), so its not like I wouldn't know what it is.
Install Alpaca flatpak, and use tinyllama or bigger LLM models.
Alpaca is nice. GPT4All is also another one (and one that I prefer). Either way, both are good. But again like previous point, I do not recommend to install and use Ai modesl (LLMs) to learn about Linux and to get used to it. Especially the smaller models often hallucinate and lie with false claims. If you don't know it better and are currently learning, this could be a problem. I highly discourage from installing and learning with an Ai model alongside when you are new to a topic like Linux. Its also not like there wouldn't be enough good material out there anyway.