As you can probably already tell, it takes a while to get a full rune page of tier 3 runes. Instead of buying a very limited use, set of runes, some people prefer to have a universal rune page.
Most universal rune pages are setup to be for either Attack Damage (AD) or Ability Power (AP) champions.
Here are two solid universal rune pages which are good to have available until you can step up to the more detailed and focused per champion pages.
9x magic pen marks
9x mp5 seals
9x ap per level glyphs ( some prefer flat CDR )
3x flat AP
9x Armor pen marks
9x flat armor / use the mp5 sealsif it’s an AD that runs on mana or has mana issues
9x magic resist per level glyphs
3x flat AD
*This is obviously this is not optimal for every champion but at the minimum it will give you a jumping off point that will at least hold you over with an advantage for those types of champs in general.
If you feel you have a better one, please shoot me and email or just comment and I will add the rune set if I approve of it!