You can use any camera you have – your phone, a small point-and-shoot, or a DSLR. Taking photos outside requires you to really focus in on the nature around you. Look for unusual colors, patterns, or animals to photograph. A botanical garden is a great place to visit to take photos, because the displays are usually arranged in eye-catching ways. You can also visit a nature preserve and looking for photo opportunities with animals or plant life. You can take a journal outside with you or wait until you get home to write. Describe what you smelled or heard or saw, and how you felt being outside.  For example, you could focus on one thing while you're outside - the way flowers work, or the bird calls you hear. Then write as much as you can about your focus. You can also use your experience outside to tap into your emotions. How did sitting outside make you feel? Describe your emotions. You can make art while you're still outside, or you can get artistic after you get home. You can paint or draw or sculpt what you see, or go for a more abstract piece that reflects how you felt about your time in nature.  It can be helpful to take a photo of what you want to paint or sculpt so you have a reference when you get home. You can paint a particular plant or animal that you saw that caught your attention. You can also paint something more abstract, using paint to express how being outside made you feel. If you want to maintain your interest in nature, think about starting a blog. You can use it to write entries about the things and feelings you experience while you're out in nature. For example, you could write entries about new nature preserves you've seen, flowers you've never encountered before, and other exciting nature experiences.

Summary:
Take photos. Journal about what you see. Create art inspired by the outdoors. Start a blog.