Thanks for your questions. If you are interested in the field, then it’s great that you are considering chemical engineering. With an A in Chemistry and a B in Physics, that is an excellent start. The main thing is your interest and what you would like to do ultimately with a chemical engineering degree. There is a lot of information online about the top schools for chemical engineering.
For example, you can see:
MIT, Stanford, UC Berkeley, U. MN, U. of TX (Austin), U. of Wisconsin Madison, UC Santa Barbara, U. of Delaware- are all examples.
But one of the most important things is to get a feel for the type of school you like- large ivy league or a state school. If possible you should visit or at least view their websites.
As for getting your GPA up, you can practice other skills like test taking and study habits. A book you may be interested in is Dancing with Your Books, the Zen Art of Studying. It helps develop concentration skills and study habits. There are numerous other sources to help with increasing focus and improving your overall grades, regardless of subject.