1. Do I have to take EIT test and wait for couple of years and take FE test for PE certificate?
First of all, the "EIT test" and the "FE test" are just two different names for the same thing. If you take the "Fundamentals of Engineering" (FE) test, California will issue you an "Engineer in Training" (EIT) certificate (assuming you pass). Then you can take the "Principles of Engineering" (PE) test, and get a PE certificate (assuming you pass).
You have sufficient education and work experience now to qualify for both the FE and PE exams (assuming that your degrees are ABET-accredited or foreign equivalent, and assuming that your non-US experience is acceptable to the California Board). However, California won't let you take both exams in the same session. If you pass the FE exam in one session, you could then take the PE exam six months later, in the next session.
2. Which EIT/FE exam should I go? Chemical or environmental?
Or you could take General or Civil. General is good if you want to minimize the amount of material to study for the FE exam. You have to study General topics for the morning half of the FE exam anyway, so it's obviously simplest to continue with General topics in the afternoon half as well. However, a discipline-specific exam is good if you want to get a head start on the PE exam.
The Environmental FE exam won't help you with the PE exam, though. California is one of a few states that does not offer the Environmental PE exam.
If you plan to take the Chemical PE exam, then you might want to start with the Chemical FE exam. However, California has an unusual two-tier licensing system for PEs. In practice, Chemical PEs have much more limited authority than Civil PEs in California. So a Civil PE may help you more professionally than a Chemical PE.
If you decide to take the Civil PE exam, then you might want to start with the Civil FE exam. But note that Civil PE candidates in California also have to pass two supplemental exams, on seismic and surveying issues, in addition to the national Civil PE exam.