Learn French: Nous voulons prendre des photos dans le parc.

Because it comes right after the conjugated verb voulons. In French, when two verbs are paired together like this to express an idea, only the first verb is conjugated. The second stays in the infinitive (the dictionary form). This is exactly how the verb pouvoir (can) works too!

How is voulons related to pouvoir, which we are learning in this lesson?

Voulons comes from the verb vouloir (to want). Pouvoir (to be able to) and vouloir are often taught together because they have very similar, irregular conjugation patterns. For example, nous voulons (we want) sounds and behaves a lot like nous pouvons (we can).

Why is there a des before photos? Can I just say prendre photos?

No, you cannot drop the article in French. While in English we can simply say 'take photos', French requires a small word before almost every noun. Here, des acts as the plural of un or une, and it roughly translates to 'some' (we want to take some photos).

I have seen prendre used for food and transport. Is it also the right verb for taking a picture?

Yes! Just like in English, you use the verb prendre (to take) to talk about taking a photo. You will also see it used for taking the train (prendre le train) or having a meal (prendre le petit-déjeuner).