Got a manual in the mail I wouldn't dare try without one, watched too many bad reload videos to try anything without knowing what I was doing
all the powder manufactures have loading data online at their websites.
thats the safest place to get data to start with.
there is an infinite number of calibers and also powders, what works in a Magnum don't usually work in a non magnum caliber best, what works in a rifle don't normally work well in a pistol.
Many pistol powders started life out as Shotgun powders, so lots to learn.
depends on what you want you cartridge to do as well, reloading for target rounds is seldom the same as reloading for hunting or defense rounds.
Any of the American Primers are fine, the foreign primers may be hard and cause difficulty in some weapons.
I would guess that Unique is likely the most universal powder out there, but even its not the best choice in every case and it don't drop measure worth a flip.