My first camino was along the Portuguese route, age 58. My second was from Sarria at age 60. I walked from SJPDP at age 66 (my 6th camino), and my last camino was completed at age 69 along 3 separate routes (Jesus Trail in Israel, Via Francigena from Tuscany to Rome and the Camino Finisterre). I'll be on the trail again in late May.
You will be fine. There will be plenty of other hikers by May along the Frances (some fo them very seasoned) for guidance. Just remember that it is not a race. Pack light-- remember that Spain is not at the end of the world. You could purchase anything you might need there, so there is little need for "just in rare case" items.