In general, people in the Netherlands (often informally referred to as Holland, though Holland technically refers to two provinces within the Netherlands) are known for being quite understanding and accommodating when it comes to language, especially Dutch. Dutch people are generally multilingual and often speak English well, so they are accustomed to interacting with non-Dutch speakers.
If you speak Dutch, even as a non-Dutch person, most locals would appreciate your effort and show a positive attitude towards it. Using the local language, even if your proficiency is limited, is often seen as a sign of respect and interest in the culture.
In many cases, Dutch people might switch to English if they notice that you're struggling with Dutch, not to offend you, but to facilitate communication and make you feel more comfortable. This is particularly true in urban areas and tourist destinations where English is commonly used.
However, it's essential to keep in mind that individual reactions can vary. Some people may be delighted that you're trying to speak Dutch, while others might not react as positively. Just like anywhere else, it's best to approach interactions with openness and respect for local customs and language practices.
If you're visiting the Netherlands and want to learn some basic Dutch phrases or practice the language, most locals would likely be happy to assist and encourage you. Just be polite, appreciative, and open to the cultural exchange, and you'll likely have positive interactions.