You need 1 variation of many different openings as White.
If you choose 1.e4, you need to know one line against 1...e5, one line against the Sicilian, one line against the French, one line against the Caro-Kann.
If you choose 1.d4, you need 1 line against the Queen's Gambit Accepted, one against the Queen's Gambit Declined, one against the Slav, one against the Semi-Slav, one against the Nimzo-Indian, one against the Grunfeld, and one against the King's Indian.
As Black, you need to know every variation of 1 opening against 1.e4 and every variation of one opening against 1.d4, like I play the French against 1.e4 and the Dutch against 1.d4. With the French, you gotta know the Winawer, Tarrasch, Advance, Exchange, KIA, Reti Gambit, and Wing Gambit. Etc.
 
     
     
     
    
I am a beginner but pretty solid with the basics. One thing that stumps me that I have not been able to get an amswer to is should you have 2 different openings? One for white one for black or do you stick with the same opening for both?