停车场在哪里？

Just say the phrase as it is. You can add 请问 (qǐngwèn) at the start. This means 'may I ask.' It makes you sound much more polite. If you are driving, you can ask a security guard. You can also ask a passerby on the street. It works perfectly in GPS voice searches too. Just speak clearly and emphasize the 哪里 at the end.

Use it when you arrive at a restaurant. Use it when visiting a friend's apartment complex. Use it at a massive shopping mall. It is great for busy city centers. If you see a 'P' sign but no entrance, ask! It is also helpful when checking into a hotel. Even if you are texting a friend before arriving, this works perfectly.

Don't use it if you are looking for street parking. For that, ask for 停车位 (tíngchēwèi) or a parking space. Don't use it if you are on a bicycle. There are specific spots for bikes. Also, avoid using it if you are in a 'No Parking' zone. That might get you a ticket instead of a spot! If you are in a tiny village, there might not be a 'lot' at all.

Parking in major Chinese cities like Beijing or Shanghai is a sport. Spaces are scarce and often underground. You will see many security guards in yellow vests. They are the masters of the parking lot. Asking them is often faster than using an app. Many lots now use license plate recognition. You might not even see a paper ticket anymore. It is all digital and very fast.

If you want to be super brief, say 哪里可以停车？ (Where can I park?). In Southern China or Taiwan, people often use 哪儿 (nǎr) instead of 哪里. You might hear 停车场在哪儿？. If you are looking for a specific type, like underground, say 地下停车场. If you are in a rush, just say 停车场? with a rising tone. People will understand your desperate look!