You can find locally popular fruit juice in a big mug known as "air buah gelas besar". Many choices of fresh fruit juice are available. You can find it in Seberang Takir about 5 km from KT on the road heading to Kuala Terengganu airport. It operates from ~ 5 p.m. to midnight.
You can also buy a variety of different fresh fruit juices, coconut water, etc. from vendors outside the Pasar Besar in Kuala Terengganu.
There are reportedly no more than 10 bars in town. Kris n Cheng, near the waterfront, has pleasant owners and is good for darts, drinks, and light singing.
Locals are mostly made up of Muslims, but you can find alcohol supplies in the most chinese restaurants around Chinatown. Do not drink publicly as this will often offend comunity surrounds you. You can drink at any restaurant which providing them, or back at your hotel room.