The simplest might be to use an app.
On Android, Heavens Above, a product of the 25-year-old website of the same name, stores the orbital elements of the satellites of interest, and does the pass calculations on your phone.
The app uses the GPS to find your location. It likes to get fresh elements from the Internet on startup, but it caches them, so as long ...
To track the satellites, you need the TLE orbital coefficients.
Once you have those, you can track the sats without internet access.
The TLE's are accurate enough for about a week. The TLE file format is standardized and works with nearly all the tracking software, and most software either downloads them on command or can import from a file.
As already ...