Your bottom bracket shell appears to be Italian threaded (36 mm x24tpi) but the exact type and design of bottom bracket you need will depend on the crank you have. Your fork is a 1" (25.4 mm) and you need a 1" threaded headset and a 1" "quill" stem of the proper length and configuration.

However, based on your questions, it seems to me what you really need is a reliable bike shop or access to a bike co-op to provide the exact items you need and the ability to install them properly.