Bamboo Leavesf Tea

We tend to use the singular form in the names of food and drink (eg: banana smoothie, apple juice)

In a local restaurant, we tasted the bamboo leavesf tea for the first time.

No need for "the" here, feels most natural without it

Normally, green teas taste a bit bitter, but the bamboo leavesf tea iwas not bitter at all.

Since you're talking about multiple types of green tea it should be plural
Since you're discussing the specific bamboo leaf tea that you drank it makes sense to talk in the past tense here

I've never known that bamboo leaves can be made into tea.

"made to" feels unnatural here. The more natural phrase for describing the processing of something into something else is "made into".
"made to" is used in certain contexts:
"I was made to walk home in the rain" - I didn't want to walk home in the rain, but someone or something made me do it
"made to order" - each item is created when the order is received, usually implying a high degree of customisability
"the machine was made to turn parts into cars" - describes the purpose of the machine, it was created for the purpose of turning car parts into cars

It's made of the new baby leaves of bamboos, which must costtake a lot of labor to pick them up, so ithe price is quite expensive.

This sentence felt a little unnatural so reworded to make it read more smoothly. "which" serves to link the part about requiring labor to the baby bamboo leaves
When talking about how much labor something takes we tend to use the words "takes" or "requires". "costs" isn't strictly wrong and people will understand your meaning, but it's slightly less natural wording
"the price is quite expensive" also feels a little unnatural. We would tend to either describe the price as "high" or "steep", or describe the item itself as "expensive"

It's a specialty of Hui Zhou, which is not easy to buy in other places, so we bought a big sack of tea leaves before going back home.

Again this sentence needed something to link the part about not being easy to buy to the tea

If you don't like the bitter taste of green tea, maybe you can try bamboo leavesf tea.

Bamboo Leavesf Tea

Leaf sounds more natural here because the bamboo is processed to make the tea.

During the holiday for National Day holiday, my family and I traveled to Hui Zhou（惠州).

In a local restaurant, we tasted the bamboo leavesf tea for the first time.

Same reason as the title.

Normally, green tea tastes a bit bitter, but the bamboo leavesf tea iwas not bitter at all.

Since you are referring to the bamboo leaf tea in the context of a past experience I you should use "was".

I've never knownew that bamboo leaves can be made to tea.

Saying "I've never" sort of implies that this is still the case, rather than that you recently learned that this isn't true.

It's made of the new baby leaves of bamboos, must costIt needs a lot of labor to pick them up, so the price is quite expensive.

Here you could either say "It's very expensive to pick them" or what I wrote above. What you wrote sort of combines the two so it feels a bit confusing.

It's a specialty of Hui Zhou, so it's not easy to buy in other places, sothus, we bought a big sack of tea leaves before going back home.

There needs to be a connective word between "It's a specialty of Hui Zhou" and "not easy to buy in other places". I switched where "so" was only because it sounded better but where you had it wasn't wrong.

If you don't like the bitter taste of green tea, maybe you can try bamboo leavesf tea.

In a local restaurant, we tasted the bamboo leavesf tea for the first time.

Normally, green tea taste a bis somewhat bitter, but the bamboo leavesf tea is not bitter at all.

"A bit bitter" is grammatically fine, but for style I suggest avoiding the repeated "bit bit(ter)" sound.

I've had never known that bamboo leaves can be made into tea.

It's made ofrom the new baby leaves of bamboos, and must costtake a lot of labor to pick them up, so the price is quite expensive.

If you don't like the bitter taste of green tea, maybe you can try bamboo leavesf tea.