The halving is near, and as many of us know, it will slow the amount of coins "minted" each time the miners find a block. I understand the basic of supply and demand, and I also know that the lesser the supply is, the higher the price. But what if there is a less supply but also less demand on the other side? Would the price still be high as expected? Or will it be low because apparently there are no buyers on the other side of the market?
Confused here. Please help.

It really depends on the demand.
Bitcoin has a decreasing supply and a large demand. If there was a low demand, it'd barely be a hundred dollars.
The supply of bitcoins is not decreasing. It constantly increasing, currently at the rate of 3600 per day. After the halving next year, it will continue increasing, but at a rate of 1800 per day.
The answer to the original question is that as long as the positive shift in market demand continues to exceed the positive shift in market supply, the price will increase, otherwise it will decrease. Market supply and demand are influenced by many factors including adoption, hoarding, the money supply, the velocity of money, and the price itself.