Download the MODX Reference Manual and check pages 107-130.
Actually, check the whole manual if you ask me, but the answer to your question starts on page 107.

thanks a bunch!!

There are also tutorials and videos available here and elsewhere. Each PART has two LFOs - each can do something slightly different in terms of target parameters. Envelopes in Yamaha synths are part of Envelope Generators. There are three basic types: amplitude (volume/level), filter (brightness), and pitch (frequency). AEG, FEG, and PEG for short. Each of these has a menu under each PART for AWM2.

MODX has two engines. AWM2 which is sample based a.k.a. "ROMpler" and FM-X which is frequency modulation based synthesis. FM is different from analog - particularly when you have two serial stages (modulator + carrier). Rather than do a crash-course on FM - the main point is that there is no true or emulated analog engine in MODX. Therefore, you will not find oscillators that are exactly like an analog system. There are lots of components that are found in analog synths - there's just no fully fledged analog engine (or digitally emulated analog). The closest one can get to the kind of control analog has is FM-X. Sometimes AWM2 (samples) can sound more "authentic" but going this route will remove some real-time control over the shape of that sound - as sample playback will be more static generally. There are lots of things to modulate - even in AWM2 - like cutoff, effect parameters, pitch, etc. So for sample playback - MODX has lots of opportunity to shape the sound.