Antenna thoughts.

Build a quarter wave ground plane antenna with a turnstile antenna as a reflector? Try to receive in the VHF band.

See this video:

How to Build: Ham Radio 2 Meter Quarter Wave Antenna - K7AGE -- Apr 9, 2014 https://www.youtube.com/watch?v=HkmD3Sgz7Q0

Also see:
https://en.wikipedia.org/wiki/Turnstile_antenna
Just the bottom half of this, the top half will be the quarter wave antenna.
(https://en.wikipedia.org/wiki/Antenna_types#/media/File:SatelliteAntenna-137MHz_closeup.jpg)

How do I know the spacing between the quarter wave antenna at the top, and wave antenna at the bottom?

Use an RTL-SDR. Use welding rod as wire.

https://en.wikipedia.org/wiki/Reflector_(antenna)

For now, don't worry about this:
https://github.com/Blockstream/satellite
(it requires different hardware it seems)

If you want to do LoRa uplink/downlink try FoSSaSat.

#302 We build a 20 Dollars LoRa Satellite Ground Station and we follow the FossaSat-1 launch
https://www.youtube.com/watch?v=5k0aM-PJzo8

or Lacuna Space
https://www.youtube.com/watch?v=n911zTNIn8E
#305 Transfer a LoRa message through space to my PC before 2020?

It looks like you would want to stick with the {Quarter Wave}/{Ground Plane Antenna} as it might be easier to find satellites (rather than one or just a few!)

More:
https://amsat-uk.org/satellites/frequencies-of-active-satellites/


https://www.rtl-sdr.com/category/satellite/


https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weather-satellite-images/


https://w5nor.org/antennas/
(so you can get an idea about parts and sizing)

https://sites.google.com/site/lowpowerradio/home/the-flying-v-antenna---a-directional-dipole-with-50-ohm-feed-impedance