watasi ha sizukana kouen de syasin wo torimasu.

は (wa) is the topic marker. It tells the listener “I” is the topic we’re talking about.
By contrast, が (ga) marks the grammatical subject, often introducing new information.
In this sentence, we’re not introducing who is taking photos—we already know it’s “I”—so we use は to set the frame of reference.

で marks the location of an action.
Here, 公園で means “at/in the park.”
Whenever you say “do something somewhere,” you use で to show where the action happens.

静か is a na-adjective. When a na-adjective directly modifies a noun, you insert な between the adjective and the noun.
静か (quiet) → 静かな公園 (a quiet park).

を marks the direct object of the verb.
In 写真を撮ります, 写真 (photo) is the thing being taken, so を shows it’s the object of 撮ります (“take”).

撮ります is the present/future tense in the polite form (-ます form) of 撮る.
Depending on context, it can mean:
• A habitual action (“I take photos [regularly] in a quiet park.”)
• A future action (“I will take photos in a quiet park.”)

Yes. Japanese often drops the topic or subject when it’s clear from context.
So you can simply say 静かな公園で写真を撮ります and a listener will understand “I” if you’ve already established who’s speaking.

• で indicates where an action takes place (“do something at…”)
• に indicates the goal/destination (“go to…”), time point, or where something exists
Example:
– 公園で遊ぶ (play at the park)
– 公園に行く (go to the park)

Just switch 撮ります to its past polite form 撮りました.
So you get:
私 は 静かな 公園 で 写真 を 撮りました。