Maybe use the New Syntax at first...
new => int
new String:stringname[size] => char stringname[size]
public Action:ActionToDo(client, args) => public Action ActionToDo(int client, int args)
public OnPluginStart() => public void OnPluginStart()
public Handler(Handle:menu, MenuAction:action, param1, param2) => public int Handler(Handle menu, MenuAction action, int param1, int param2)
etc...
If you search "Sourcemod Menu API", you will find more about Menus.....
And so on... If you search on google, You will find more of what you are looking for..
Also, there is no need to use that many spaces..
Now onto the code itself, i suggest you don't really know what you are doing (correct me if i'm wrong)
and that this is a copy-paste from another person's code... So i suggest either using that person's plugin, or keep trying it yourself.. Since you will have to learn on your own... This won't come by just copying- and pasting over codes...
A few useful links that also contain what i said:
https://wiki.alliedmods.net/Menu_API_(SourceMod)
https://forums.alliedmods.net/showthread.php?t=244092
Conclusion: i think you need to rewrite this code... (Correct me if i'm wrong..)