Best way to do a steak on the BBQ?

I am a ummmmmmmmmm bad cook (to put it mildly! LOL). Just bought a BBQ and going to get a good steak tonight. Cant do a quality cut (working class so no prime rib lol) So any suggestions regarding cut of steak,cooking times,spicing, and maybe a lite marinade (Dont like a strong on as it takes away the flavour of the meat so teriaki is out). Like my steak medium rare.
Yes I will put up the 10 points!
Thanks in advance!

Ok KING of the Barbies Here From Australia. Put the spices/ even little garlic crushed / maybe a little soy sause as it helps with the browning.and leave the steak at room temp for at least 30 to 40 mins ( hope it a little warm there) Then get ya Barbie up hot just before it starts to smoke.. Wack some olive oil on the steak and get that mother on the barbie. and only turn it three time. It medium only after a 4 to 5 mins
( takes practice). Then let it sit for a min after cooking so ya don’t lose the juices… On ya MATE!!