Danish oil, 500ml cola bottle, cling film. Dispose of cola as you see fit, rinse and dry bottle. Cut top off bottle just below the cap, fill with oil, submerge knife blade uppermost after you have done all your shaping and sanding. Wrap clingfilm around the open mouth to cut down on evaporation. Leave it to soak for 24+ hours. Take out, wipe and allow to dry for a week. Size of opening and amount of oil chosen so that you don't spill it everywhere when you put the knife in. Knife in first risks you cutting yourself, or knocking the thing over, so oil in first is better
Varnish always looks terrible and tends to say bad things about the maker.
The exception may be one of the catalyzed varnishes (Rustins Plasticoat was one, I think) or cyanoacrylate superglue. These both require a lot of work to finish well and are worst on a full tang. Not recommended for a beginner wanting a working tool.
Danish oil soaking is not the nicest oil finish, and not the "best" for looks by a long way, but it is durable and very easy. Value to cost is good.
Not sure what "Brazilian Oak" is, maybe Tauari (
Curatari oblongifolia)? Not going to be the same as oak (Quercus).