Guideline on making dedicated server

I’m not sure if this is the right place to ask or not its my first time here but :

can anyone please give me a step by step Guideline on how to make dedicated server . i execute my game , and i putted -server in game properties and that part is fine . but how can i connect clients to my server ? i know that i have to open port 7777 on the modem of the server but i have problem there but anyway i will fix that , but if anyone could give me a clear step by step guide line i would totally appreciated . thanks in advance