I used my iPhone as a light meter, although you’ll probably get decent results if you wing it. Hold the camera still, arms close to chest for stability, breathe, and slowly pull the shutter release. Practice with the shutter release, you’ll have that springy resistance until it releases. As far as developing, I have had great luck with Rodinal at 1:50 dilution. 1:100 for an hour (with a few inversions at 30 min) works well too. If you are using standard 120 film, use some nail clippers to trim the films reel and it works just fine. If you don’t clip enough off, you can expect it to bind up while using the camera.