so i reinstalled gmod 3 days ago and installed everything i need to join the server (css,perpcontent,hl2ep1and2) but when i join the server i see missing textures and errors would appreciate it if someone helped
Are you sure the games are fully installed and not just started downloading on steam? Also, when you launch Garry's Mod, check the game icon on the bottom right side of the main menu. Click that, and make sure the games you mentioned are enabled. If all of these are okay, you should be good to go. Maybe try installing HL2 too.
You may want to download the content pack. (The download button on the menu bar of the forums) It contains all of the content you will need for the server excluding the map. To get the map go to the collection on the workshop which contains all of the content for it by Xquality.
i installed CSS and HL2ep1and2 manually without installing the games and i also got all the constant i need for the server but i still see errors (i installed everything the same way as they were before i reinstalled gmod and the use to work perfectly before the reinstall)