Check examine.com
They have supplement guides for different goals.
I use Orivedas Lions Mane extract. The nice thing about lions mane is that it’s also believed to aid to create new pathways in the brain. I believe that will help tremendously working with subliminals because they also create new pathways (new mindset, new ideas, new thoughts, new beliefs, different perspective).
Anyway, I use so many supplements I am unsure what works for what. But make sure you get a good quality daily vitamin, omega-3, vitamin d and perhaps magnesium/calsium. Those can help, before jumping into other stuff. Get the basics handled.
A very good way to improve cognitive functions:
A patented, bioavailable form of magnesium, developed by scientists at MIT, increases synaptic plasticity and reduces brain aging by 9 years
https://www.lifeextension.com/magazine/2020/6/magnesium-l-threonate-regenerates-brain-structures
That means it helps existing synapses work better and also increases the overall number of synapses.2,3,7-10
These effects translate into improvements in cognitive function, including better learning and memory.
If you’re interested in nootropics, I suggest you check out TheNootropicReviewer on YouTube. Lots of great info on his channel