Something relatively inexpensive that’s also fun is geocaching, it’s like hiking but there’s a scavenger hunt involved. I remember doing it with my cousins on family trips when I was younger. It’s a little childish, but it added a nice bit of variety to the hikes we would go on. I would also suggest learning something that excites you via Khan Academy or YouTube, I recommend knitting/crocheting, Pixar animation, and coding, but there’s hundreds of possibilities.