Golfing tips NEEDED please!!!?

Ok so I'm 16 and started to golf for fun 2 weeks ago and I went to the driving range once and did alright all I care about is hitting the ball right now. Which is where I need help. In my yard probably a few times a day for like a half hour I go out with a 9 iron(closest to a wedge I have) and hit balls. I'm guessing 60% of the time I "top" the ball which is incredibly frustrating to chase the ball 10 feet and hit again, 20% of the time I take a chunk of dirt out before the ball without even touching the ball or just touching the ball with the side of the club and have it fly way left(I'm a lefty). 10% is that rare perfect hit. But that's only at first. If I can hold myself together and stay out there I hit more and more good hits until I get it almost everytime. Buttttt then the next time I cone out it's like in starting from scratch which is so frustrating because I know I can hit a good ball. I use the interlock grip and my pinky finger is getting a little sore but not bad. So is there anything to practice to keep doing good?? Cuz I just don't wanna be holding people up at the golf course and embarrassing myself