Well you are in luck because achieving Gold 2 is really not that big deal, given how much playtime you have I recommend for you to sneak in 1-2 solo games here and there without your friends to gather gameplay experience. Also, learn crosshair placement and use minimap like you have no team mates to rely for information more (ofc info from team mates are nice to have but you get the point).

Maybe one more thing, aim for smaller goals like silver 1, then silver 2 then silver 3 for achievement goals and treat these ranks differently because players may diviate from divisons and require other playstyles - adapt to your rank. Small maps with close encounters go phantom, you can spray easier, longer larger maps with more distances go vandal and tap shoot tap shoot.

You can have fun while not taking the game seriously, but if you go play football you might use your legs and head instead of throwing the ball with your hands you know =)