Brandi, Dale is correct but he answered a different question - you should SLOWLY crack the tank valve til you start seeing pressure come up on the high pressure gauge - once it's up, open the valve all the way. The OTHER gauge (if there is one, instead of a rotometer) is your flow rate - I too set mine at 20 CFH. BTW, that IS a pressure gauge too, but it measures the pressure DROP across an orifice in order to show FLOW rate. Some regulator sets use a rotometer (bb in a tube) to measure flow, either one is fine.
Another change from what you're used to - weather's gettin' warmer, but if you try to weld with 75/25 and have a FAN blowing on you to keep cooler, you will NOT like the welds - you're into animals, pick your favorite excrement and your welds will look worse - Same thing when (not IF) you forget to turn on the gas before you weld - anybody here who claims they've NEVER done that is almost guaranteed to be LYING
Have fun... Steve