You must be licensed by the FCC before transmitting on amateur radio frequencies. If you can’t find a class, you can prepare for the test online and with books.

The question pool and correct answers are publicly available. You can take practice tests online. You’d be surprised at how many questions you can answer correctly merely by eliminating the obviously wrong choices. Then just study the areas you are weakest on. Go back and take another test and repeat till you feel ready to find a testing session and take the test.

Here are some useful links:

The Technician Exam question pool (correct answer in parentheses)

All the question pools

Online Practice Test from AA9PW
Online Practice Test from eham

ARRL Books
Gordon West Books

Online classes
Other resources