Go here for a note on progress in updating to Space Age & 2.0
BZ mods will always support picking and choosing your own loadout, so you can choose one or two and just get started. But if you like, here's a guide to get you started.
BZ Bees: Basic Metals | BZ Bees: Basic Electronics | BZ Bees: Intermediates | Very BZ
There you go! That should be all you need to get started.
If you're interested, here's a diagram of what is in each modpack.
