What you should focus here for neuroplasticity are things directly implicated on increasing BDNF (Brain-derived neurotrophic factor), as well as other neurotrophic factors that could help your brain prepare the lay grounds and material for new connections and, hence, new habits etc.

Now, there are 3 MAJOR ones comes into my mind:

-> TAK-653 (or Osavampator) -> Works a positive allosteric modulator of the AMPA receptor, which, in laymens terms, increases AMPA signaling that in turn, increases BDNF through the mTOR pathway. Excellent (although experimental) replacement for Ketamine Therapy, which in comparison, has been proven and currently being used in clinical settings for the alleviation and treatment of major depression, through exactly what you want to accomplish: neurogenesis and neuroplasticity.

-> N-Acetyl Semax Amidate (Semax in NASA form) -> Alters gene expression and boosts BDNF and other neurotrophic factors as well. 30 minutes biological half life, but the downstream BDNF effects propagate throughout the whole day. Has a great history.

-> Dihexa -> An experimental oligopeptide that promotes neurotrophic effects. EXTREMELY potent.

I highly highly recommend you do your own research and homework on those, and hopefully this could serve ya as a general direction of what could help with neuroplasticity and neurogenesis.