Hi,
A few things to note when cooking steak.
1. Gas grill temp should be Med High.
2. Let the steaks get to room temp before you grill them.
3. Once on the grill turn only once. You can do a google search for how many minutes on each side for desired doneness. The softer the teach to the touch the rarer it is. A chef once told me to touch your fatty part of of your insided arm below the elbow - should be pretty soft. That would be rare. Now continue up your arm to the wrist. Wrist should be pretty hard - that would be well.
4. When the steak is done - DO NOT cut into it. Wait 5 minutes or more before you cut it. If you cut it too soon the juices have not redistributed throughout the steak yet and the steak will not be juicy.
T-bone steaks are great, NY Strip too. Those have a bit more fat which equals flavor. The more marble in the steak the higher the fat. Rounds or sirloins are also really good but have a bit less fat. I eat them all. I love steak but will not eat if over cooked.
It is tricky for me and I have grilled many. Good luck. That is such a sweet thing to do.
One marinade I like is a bit of worchestershire and au jus (non diluted), marinate for a 1/2 hour, dry them off and brush with olive oil, and season with steak season.
Winter