kraljmehmet xampp?
ok listen for now im giving you the zip (? modded, read the guidelines) which contains whole package, just extract it under htdocs and open in browser, add db creds and you are good to go.
but again for installing extensions you'll need composer so download composer from here https://getcomposer.org/download/ then after installation, open the directory of flarum, hold shift+right cick, open command/powershell window here then you can continue with installation of packages
Still before using the zip try to do it on ur own by just typing composer create-project flarum/flarum . --stability=beta
