Good advice from 3rdI already.
Let me add this: You can smoke caapi vine, but it isn't very tasty. Extracting harmalas and adding them to your plant materials is a very elegant way of approaching it, but even small amounts of harmalas will have a great effect if smoked. So your vine is sufficient.

With what you have, i'd just use caapi vine and infuse it with dmt 1:1.
Before smoking your changa, i'd follow 3rdIs suggestion and try some caapi beforehand, see how it feels.

2g is plenty to experiment with. Just make a small amount of changa and then try it.
If you want to continue with DMT, you'll have all the time in the world to try all the elaborate techniques later...blue lotus, extracted harmalas and whatnot...

(blue lotus is pretty psychoactive on its own, so i'd test that solo first!)

It is very easy in the begining.