There are two ways to get to the island- well, three, if you include swimming,... but most people will choose one of two options:
There are two companies that operate boats to Catalina Island -

Catalina Express – Takes you to Catalina Island in just over an hour with up to 30 daily departures from Long Beach, San Pedro and Dana Point. Book online at https://catalinaexpress.com or call (800)613-1212. They have senior discounts available for ages 55+. Current fare is $85.50 round trip for seniors. You can book several months ahead.
Parking at the terminal costs $25/day, so carpooling or Uber is a great idea.
Note: Be sure you are booking a trip to Avalon, not to Two Harbors.

Catalina Flyer – Has one daily boat to Avalon out of Newport Beach. (949)673-5245
Senior Discounts
https://catalinainfo.com
If you love to fly and have money to burn, contact Maverick Helicopter at: https://maverickhelicopter.com or call (702)728-4241