Fielding: There are hundreds or drills and exercises you can do to improve your fielding skills. Play catch, start close together throwing lightly back and forth. As you loosen and warm up move further apart. Everyday as you get stronger and you start building up your muscles you can throw harder and move even further apart.
While playing catch with a parent, sister, brother or another player, see how fast you can catch the ball and cleanly get it out of your glove and make an accurate throw. Do this of every catch, you can put this right to work in real game situations. There are a lot of nice pitch and catch units out there which will let you throw and the ball comes back to you almost as fast. When using one of these pitch and catch units set it so you get grounders back or high line drives. You can also throw at an angle and the ball travels back at the opposite angle, this gives you a chance to grab balls coming back to you on the run. Exactly like game conditions.

Fly-balls: Practice catching fly balls. You don’t need a bat and a park with Dad hitting 200 ft. fly balls. That would be great but there are other ways. Have Mom or Dad throw you some nice rainbow throws, 30ft., 40ft. Or 50ft. They can throw underhand or overhand anything that looks like a pop-fly. Don’t throw directly to the player make them work, throw to the left side, to the right side or behind them. This is the best way to learn over the shoulder catching. Use wiffle balls, rubber balls or softballs. Practice works.

One of the biggest fast pitch fallacies: Better players play the infield positions.
Wrong, WRONG, WRONG!!! This is a carry over from your younger days. You showed up to play Townball or Recreation ball and the coach said grab your glove and go to the out field, where you just stood for the next 3 outs. At that age no hitters could hit out there, most of the hits were short grounders that could be picked up and thrown to first for the out. So naturally the coach wanted his best players at 1st, 2nd, SS and 3rd, just to stop the ball and throw it to first.
In High School and College softball the outfielder position is critical to a teams success. Most good hits that go on to score, get through the infield or are hit in the air to the outfield. If the outfielder doesn’t make the catch the hitter usually ends up at 2nd. When one gets through the infield to the outfield, the fielder must know where to throw to prevent a runner from scoring or to hold a runner at first.
Probably the most important job of the fielder (other then catching every fly ball) is to backup the bases or the throws. Watch a really good college team or the Olympic Softball team, as soon as the pitch leaves the pitchers hand, everybody on the field is moving. Fielders are watching the ball but at the same time moving to backup a base or a throw. 1st and 3rd moving for a bunt or hit, SS or 2nd waiting for a throw down to second. Even the pitcher releases the ball and instantly gets into the defensive position. Everybody is moving.
On the best college teams, the infield and outfield watch the catchers call to the pitcher, or the shortstop will relay the call to the rest of the team. They know by placing the ball at certain locations at the plate, if hit the ball will go in a certain direction. If no one is on base you want the hit to go toward 1st, so you call for a high or low outside pitch, chances are if hit it goes to 1st or 2nd baseman for an easy out. If you have a runner on third and don’t want her to score you can for a inside pitch, if hit it usually will go toward the shortstop or third and prevent the runner from scoring.