How to install SuiteCRM?

This seems to be nightmare.

I was suprised by chmod -R 775 cache custom modules themes data upload
All these folders do not exist in the main directory. Later I was supposed to call install.php
All this only makes sense if I only upload the public/legacy/ folder to the server and ignore the rest.
Currently it gives:
" Fatal error : Uncaught TypeError: fwrite(): Argument #1 ($stream) must be of type resource, bool given in /home/public/crm/public/legacy/install/install_utils.php:732 Stack trace: #0 /home/public/crm/public/legacy/install/install_utils.php(732): fwrite(false, ‘\n2024-03-25 15:…’) #1 /home/public/crm/public/legacy/install/install_utils.php(64): installLog(‘installerHook: …’) #2 /home/public/crm/public/legacy/install.php(849): installerHook(‘pre_installFile…’, Array) #3 {main} thrown in /home/public/crm/public/legacy/install/install_utils.php on line 732"

If I only upload the legacy folder I get:

“Composer autoloader not found. please run “composer install””