Chemistry isn't something you can just learn a small piece of, you need to understand chemistry as a whole, however in this case you want to look into "organic chemistry"
Buy some beginners organic chemistry books, and do research regarding extractions in particular, acid to base extractions, straight to base extractions, and so on...
Though chemistry isn't something you want to jump into haphazardly...
What DMT containing plants have you found in your area?
You can also purchase DMT containing plants online (as well as their MAOI counterparts for ayahuasca or ayahuasca analogues, Which is far more suited to a person with no chemical knowledge)
-eg