FOR DUMBASSES: Install linux (DUH), this instruction is Debian/Ubuntu centric but you can do it on probably any linux if you just
FOR DUMBASSES: write the thing that is before the ":" + how to (mydistro) into google or something
FOR DUMBASSES: Open Terminal, if you don't know how: look it up dumbass

Install git: sudo apt-get install git
Fetch the guca into a folder of your choosing: git clone https://github.com/zkm2/shamichan 
(this is a fork of some guy with some fixes I think, basically what v6 is on the original bakape/shamichan)
Install go: sudo apt-get install golang
Install docker: that's distro specific but you can just type "install docker (yourdistro)" and there's a page for that
For example the page for debian is: https://docs.docker.com/engine/install/debian/ for ubuntu: https://docs.docker.com/engine/install/ubuntu/
Do not forget to turn on the daemon if it doesn't work: sudo systemctl start docker

OPTIONAL: Install npm: 
OPTIONAL: 	sudo curl -sL https://deb.nodesource.com/setup_20.x | sudo bash -
OPTIONAL: 	sudo apt install nodejs 
OPTIONAL: Run:	npm audit fix
OPTIONAL: (this removes some vulnerabilities, but it's still probably not very safe software, would be nice to have the meowin version running)

Move into the shami folder: cd ./shamichan
Run: go mod tidy
Run: sudo docker compose build (or sudo docker-compose build, whichever works) (get comfortable, it'll take a while now)
Run: sudo docker compose up -d
Open the browser, type in: 127.0.0.1:8000
The rest is as is in the guide on the github, basically you'd need to change the password, change the attachment size max (it's like 5 mb by default) and whatever else you want to do.
When done: sudo docker compose down