For a project in my studies, I need to design a schematic for a PCB. I've already created the following schematic, which you can see in the attached image. However, I’m still getting one error and three warnings, and I’m not sure how to resolve them.

![Image of my schematic][1]
![Image of the erors][2]
![List of parts I habe to use][3]


  [1]: https://i.sstatic.net/F0MlH5uV.png
  [2]: https://i.sstatic.net/G75fhDQE.png
  [3]: https://i.sstatic.net/67UEbwBM.png