There could be a lot of reasons. If you're new to Logic. I recommend watching Music Tech Help Guy on youtube. He has dozens of tutorials, starting from square one. This lesson is about recording with a microphone, which your guitar has. He is actually using a guitar for this 20 minute lesson.
https://www.youtube.com/watch?v=iLqNcFXHAIo&list=PLXmi76euGSyyq1nw21U1M4tTsM0Zysayk&index=15&t=1s
Also, you might want to check this:
Check the Control Center on the top right of MacOS menu bar. It's where your volume control, network setting etc are located. You should see a microphone while Logic is running. Click on it and change to standard.
Hope this helps. 