Dripstone Blocks can be found in Minecraft after talking to the Mason Villagers, who have reached the level of Journeyman, or you can find them naturally in caves hanging from the ceiling. If you use a pickaxe to unfold them, you can place them anywhere you want. The ones you find naturally have a chance to leave pointed drip stones hanging on them, which should drip water down to the ground and become stalactite. When the Dripstone Block is on the ground, the pointed Dripstone becomes a stalagmite.
Everything depends on the water source. When you place the Dripstone Block down and have a source of water above it, the block drips water. Even if it looks like dripping water, it will not be enough to fill a boiler or anything else. It’s just animation. You have to wear a pointed dripstone, and when it’s on the bottom of the block, it’s a stalactite. When stalactite with a source of water appears above the water stone block, dripping water fills the boilers. The same goes for stalagmite, but the water source must be below Dripstone’s block.
If you are waiting for a pointed drip stone to grow, you will wait quite a long time. In Minecraft, there are 20 ticks every second, and for every tick there is a 0.0113 chance of a Pointed Dripstone growing out of Dripstone Block. This means that on average you will have to wait somewhere between five days in Minecraft before it happens. As long as you are patient, it can happen.
There is no way to influence it in your Minecraft world. You just have to be patient. If you want to get more pointed drip stone, you can alternatively have a Mason Villager store with one emerald for two of them, but there is a chance that Mason Villager will not have this store available.