Learning by trial and error is time consuming and expensive. Research is quicker! There are so many people to learn from who have already fine-tuned this sport. People with experience love to share stories and favorite gear or technique they have learned. In addition to information on this web site, organizations are a good source of information. Through the Appalachian Trail Conservancy, we found our mentor, Verna Soule. Make a list of concerns and questions. Ask for recommended books and people to talk to. Ask about blogs or chat rooms dedicated to backpacking.
Take a day hike with an experienced backpacker. Ask them to look at your equipment. Start by borrowing or renting equipment so your basement isn't full of useless stuff. This industry is changing rapidly, getting more and more lightweight gear. This is VERY IMPORTANT for someone over fifty because every ounce makes a difference to the older body. A goal is to have your dry weight, (not counting food and water) under 20 pounds. You can expect to add two pounds of food per day and 4 pounds of water. Your pack should never be over 35 pounds if you want to have fun!
MAKE LISTS! Weigh everything you plan on taking and make a list of all possible supplies and gear. That way you don't have to try to remember what to take each time. Organize your equipment in plastic bins. The older we get, the more often we forget where items are. Many of the things you buy for backpacking can be used for multiple purposes, so if they are stored in one place, you won't keep buying more because you have misplaced the item.