First off, welcome! Many of us have had the same problem as you. It's common with beginners. Don't get too discouraged. Have fun.
Hempies got the idea right, but had a few terms mixed up. Here is what it should read:
Then there are nuances like high speed stability (HSS) which is the tendency of a disc to turn one direction at the beginning of the flight and low speed stability (LSS) which is the tendency of a disc to turn (or fade) at the end of the flight. On the chart I linked, the HSS is the first turn in flight as it travels 50'-150' feet (+/-) and the LSS is the fade at the end of the flight
Also the term 'turn and burn' typically refers to a throw that turns over too far into the ground during the initial high speed portion of the flight, often caused by overpowering a slower, understable disc or by having too much wobble upon release, which is called off-axis torque (OAT) and causes a disc to fly more understable than it is. Apologies for that nice run-on sentence just now.
I will definitely echo what's been said about putters and slower, neutral mids. Work with your putter especially- you would be surprised how far a putter can fly, and with much better accuracy.
Don't even try to throw your Valkyrie or Wraith yet, you may wind up creating bad habits. Don't get wrapped up in the hype that a "faster" driver will yield longer throws. A Teebird (speed 7) and many other slower discs can go just as far as distance drivers, and putters can be thrown over 300 feet.\
Good luck!
Edit: Jeez, everyone beat me to the HSS/LSS corrections. I'm a slow typer.