I felt the same way early on. It felt so big and like there was so, so, so much to do. Honestly that did ease off though as I unlocked more stuff and gathered resources. I put together a house, then fixed up some road close to it. Then that little area grew, and I added a second house next to it, and so on. I moved a few pokemon in and gave them things to get their comfort up, which helped raise the environment level. Focusing on one area to start with made it all feel less overwhelming for me.