You don't really need to worry about ores too much outside of Vanilla Ores.
Basically the main way to progress is to find affixed items (items that have extra attribute modifiers and sometimes special effects), and gems which can be socketed into these affix items in an empty socket. Both of them can be found in chests, dropped by Apothetic Invaders (mobs decked with a full set of gear and buffed attributes, will glow based on rarity), or for affixed gear, reforged with a Reforging Table, a rarity material acquired by salvaging gear of the same rarity, and Sigils of Rebirth, crafted with Deepslate and Gem Dust. Gem Dust can be acquired by crushing gems with an anvil or salvaging them.
On top of that, you can also use experience to upgrade your skill tree, which contains several skills and buffs such as extra damage, less levels required for enchanting, and extra sockets.
You'll also want to look into Apotheosis's enchanting system, which requires crafting special bookshelves and infusing them (by using more special bookshelves). This in turn allows you to get enchantments way over the natural limit.
A good combination of these will get you far into the modpack. The quality of rarities will improve as you adventure into more difficult dimensions, so just rinse and repeat until you can get a good DPS (anything over 1000 will be good). Over time, you'll be able to unlock more items such as the Augmenting Table.
For a more detailed explanation, check out the Chronicle of Shadows book