You got a lot of good feedback, and here's one other thought.
I note that the C15 has a daysailing rig of 123 sq. ft. and a performance rig of 139. If you have the latter, sailing solo in 10 to 15, you probably had your hands full, and the additional challenge of tacking with a larger overlapping jib would have added to the complexity.
Try sailing in conditions under 10 with just the main and adjusting the centerboard to balance the helm. As you get comfortable, add the jib, or add a crew to manage the jib for you.
Have fun ... looks like a great boat to learn on.
took the words out of my mouth.too many things going on at once can make it harder to get a feel for the boat.
p.s. dont sail further than you can swim when learning.