The availability of an English option for Japanese visual novels is quite inconsistent. Major releases from well-known developers are more likely to have it, but smaller or more specialized ones often don't. It's best to check the details of each individual title.
Not all Japanese visual novels have an English option. It varies a lot. Some indie or niche titles might only be available in Japanese, while big publishers might make the effort to localize for the English market.
Sometimes they do. It depends on the specific visual novel and the publisher. Some popular ones might offer an English option to reach a wider audience.