With your Tinkers' tools, you can go out to the ocean and mine Rutile Ore and Limestone.
These are the main materials you need for titanium.
To acquire Titanium, you will need to smelt Rutile Ore in a Crucible Furnace.
The Molten Titanium you get from this process is still impure, which means you will need to purify it by mixing it with Magnesium in a Vat. Magnesium can be acquired from mixing Molten Limestone with water in a Vat.

Once you have Titanium, you can start with Thaumcraft, and obtain Manasteel in Botania for a lower cost.