In general, you should expect to attend and present at ~1-2 conferences each year starting in your second year.
Some relevant conferences are listed below:
AIChE Annual Meeting
This is always a good choice to consider since it brings the ChemE community together, although it is not topic-specific.
Gordon Research Seminars/Conferences
This is a great, immersive way to partake in a conference on a particular topic of interest. Don't forget to register for both the GRS and the GRC for a given symposium.
MRS Fall or MRS Spring Meeting
The topics in the MRS sessions are often quite specific, so it can be a bit hit-or-miss depending on your interests.
ACS Fall or ACS Spring Meeting
The meeting is huge. On the plus side, there is always an interesting talk going. On the downside, it can be a bit hectic to navigate, and the turnout for each talk is often relatively low.
FOMMS
This is a nice conference for computational modeling folks within our research field.
If there is ever somebody you want me to introduce you to at a conference, I'm happy to do so!
You may wish to add on personal vacation days at the end of the conference period if your schedule permits since your flight will already be covered by myself or the university.
Funding
It is recommended to apply for conference funding support if possible. Several opportunities are included below: