DF Starter Info

I assume you're very new with Dwarf Fortress, so I'm gonna write up some instructions on how to install custom ASCII tilesets and change the colours.

Tileset:
First, go into 'data\art' in your DF directory, then place this image there:
https://cdn.discordapp.com/attachments/504754524079259678/865310989574209566/taffer.png
Then you go to the 'data\init' folder and edit the 'init.txt'. You wanna find the places in the file where it says '[FONT:' and '[FULLFONT:' and replace those with '[FONT:taffer.png]' and '[FULLFONT:taffer.png]'. The first of these is for windowed and the other for fullscreen.

If you don't like this Taffer tileset, then you can go to this link, where they have a million ASCII tilesets: https://dwarffortresswiki.org/Tileset_repository
One kinda special thing about this Taffer tileset is that if you have walls that are arranged in a "stairs" kind of pattern, then the tileset will make them look diagonal, which looks nicer in my opinion, but it's personal preference.
Here's an example of what it looks like: https://cdn.discordapp.com/attachments/504754524079259678/865595486572642354/comfy_fort.PNG
(lol ignore those faces. I replaced the icon for dwarves with that one for fun)

Colours:
Replacing the colours is even simpler. You just have to go to 'data\init' and replace the content of the 'colors.txt' with this textfile: https://cdn.discordapp.com/attachments/504754524079259678/865596532551319592/colors_Vherid_Dusk.txt
This colour scheme is called Vherid Dusk and it's a lot easier on the eyes than the default colour scheme, if you ask me. You can alternatively find lots of other colour schemes on this website: https://manmademagic.github.io/DFColorGen/

Tutorials:
I recommend Kruggsmash's basic tutorial. It's only 30 minutes long and it tells you the very basic things you need to know for starting out. He actually goes over the same stuff as I did, too: https://www.youtube.com/watch?v=eTeQJOC1H38
Besides that, the quickstart guide on the wiki is very useful: https://dwarffortresswiki.org/index.php/Quickstart_guide

Other utilities:
I think the two biggest utilities for DF are probably the Therapist and DFHack.
Therapist is a spreadsheet that opens in a separate window and essentially makes it a lot easier to assign professions to your dwarves, give them names, etc.: https://github.com/Dwarf-Therapist/Dwarf-Therapist/releases

DFHack is essentially the OXCE of Dwarf Fortress and people will probably likewise shout at you for not using it. Personally, I didn't use it for the longest time, but then I tried it and realised that there's basically no reason not to use it. It gives you access to lots of quality of life features, additional keys and screens ingame (for example it has its own version of Therapist, but it's accessible ingame, instead of being a separate window), and stuff that is useful for debugging, etc. You don't need to use it, but eventually you may want to consider it: https://github.com/DFHack/dfhack/releases