I will travel in flydubai and will have around 8 hours layover time in hand at terminal 2. Can I go to terminal 1 or 3 to duty free shop? What about getting visa also to go to buy some gold jewellery outside? Thanx. Arefin.
You cannot go to Terminal 1 or 3 from Terminal 2 without a boarding pass for a departure flight from either of those terminals.
Regarding your second question, visa on arrival depends on your citizenship. You can see the list of countries eligible for visa on arrival here.