If you're looking for a good camera for mainly taking pictures of nature and for traveling, with a maximum budget of £500, I would recommend the Fujifilm X-T5. It's a mirrorless camera that offers a good combination of portability, ruggedness, and image quality. It has a high resolution of 40 MP and a 15 fps continuous burst rate, making it suitable for wildlife photography. Additionally, it has a good low-light performance and dynamic range, which is useful for capturing images in various lighting conditions.
Another great option would be the Sony a7C II. It's a compact and lightweight full-frame camera that is perfect for travel photography. It has a 24.2 MP sensor and can shoot up to 10 fps in burst mode, making it suitable for capturing wildlife and fast-moving subjects. It also has a touchscreen LCD and a hybrid autofocus system that provides accurate and fast focusing.
Both of these cameras are excellent choices for nature and travel photography, and they won't break the bank. They offer a great balance of features, image quality, and portability, making them perfect for capturing stunning images on your next adventure.