У входа в парк растут тюльпаны.

A very literal breakdown is:

• У = by / near / at
• вхо́да = of the entrance (genitive singular of вход)
• в парк = into the park / to the park
• расту́т = grow / are growing
• тюльпа́ны = tulips

So the sentence is literally something like:

By the entrance to the park, tulips are growing.

More natural English: Tulips grow near the entrance to the park or There are tulips growing by the park entrance.

Because the preposition у requires the genitive case.

• dictionary form: вход
• genitive singular: входа

So:

• у входа = near the entrance

This is a fixed grammar pattern:

• у дома = by the house
• у окна = by the window
• у двери = by the door

Here у means near / by / at.

This is a very common point of confusion.

In this sentence, в парк does not mean in the park. It belongs to the noun вход:

• вход в парк = entrance to the park

Russian often uses в + accusative after nouns like вход because the idea is originally directional: an entrance into the park.

So:

• вход в парк = entrance to the park
• билет в музей = ticket to the museum
• дорога в город = road to the city

If you said в парке, that would mean in the park, which is a different idea.

Тюльпаны is nominative plural.

It is the subject of the sentence — the thing that is doing the action of растут.

• singular: тюльпан
• plural nominative: тюльпаны

So:

• Тюльпаны растут = Tulips grow / are growing

Because the subject тюльпаны is plural.

The verb расти = to grow
Present tense:

• я расту
• ты растёшь
• он/она растёт
• мы растём
• вы растёте
• они растут

Since тюльпаны = they, the correct form is растут.

Russian word order is much more flexible than English word order.

Both of these are possible:

• У входа в парк растут тюльпаны
• Тюльпаны растут у входа в парк

The version you were given starts with the location, which puts focus on where the tulips are.

So it feels a bit like:

At the entrance to the park, tulips are growing.

Starting with тюльпаны would sound more neutral if you simply want to say what the tulips are doing.

It can mean both, depending on context.

Russian present tense often covers both:

• a general fact: Tulips grow there
• something happening now: Tulips are growing there

So растут can be understood as:

• grow
• are growing

With plants, расти is very natural because it describes the fact that they grow there.

You could, but it sounds different.

• У входа в парк есть тюльпаны = There are tulips by the entrance to the park.
• У входа в парк растут тюльпаны = Tulips grow / are growing by the entrance to the park.

With plants, Russian often prefers расти because it is more natural and specific. It tells you not just that the tulips exist there, but that they are planted/growing there.

Yes, often you can:

• У входа в парк растут тюльпаны
• Возле входа в парк растут тюльпаны

Both mean roughly near the entrance to the park.

The difference is small:

• у often suggests being right by something
• возле means near / next to and can sound a little more explicit

In this sentence, у входа sounds very natural and idiomatic.

Because Russian has no articles.

So вход can mean:

• an entrance
• the entrance

and тюльпаны can mean:

• tulips
• the tulips

The exact meaning comes from context.

Here, English usually needs the:

the entrance to the park

But Russian simply says вход в парк.

With stress marked:

У вхо́да в парк расту́т тюльпа́ны.

A rough pronunciation guide:

u VKHO-da v park ras-TOOT tyool-PA-ny

A few notes:

• вход begins with вх, a consonant cluster that can feel difficult at first
• ю in тюльпаны sounds roughly like yu
• the stressed syllables are:
  • вхо́да
  • расту́т
  • тюльпа́ны