If this is the first time that your boat has transited the canal then you must first get measured and obtain your Panama Canal
number. This may take a few days or more to accomplish; then you can schedule the transit. If it has transited before then you can save time and money
by finding the number. I recommend that you not try to schedule your transit soon after arrival, but instead plan on spending some time in Panama
City and volunteering to be a line handler on other boats. Often you can trade
with others to help you get through. If you can't be bothered then hire professional line handlers - they will keep you out of trouble in the locks. At a minimum use other sailors and not anyone unfamiliar with line handling (like backpackers looking for the experience). Accidents do happen to boats in the locks so spend some time to learn the situation before sallying forth.