Flying with emirates

I'm flying to Kuala lumpur from tehran with emirates, Economy class, Emirates, EK971-EK346 -terminal 3
Now i want to ask if marhaba lounge is free of charge? and if the services inside is free?
And i also want to ask there was like a restaurant lounge in dubai airport, it was free of charge it was exclusively for EK travellers, where is it in the gate place, whats the name?

You'll only get into the lounges with the right card...

If you are travelling business or first class then you get access to the various lounges. If you have a silver Skywards card, then you may get access to the business class lounge that EK has in Terminal 3 somewhere near Gate 117 or so.

You should know that Dubai Airport has many places to obtain food but you need to pay and I do not think the Iranian riyal would be accepted.

Good luck.