The first of these challenges has nothing to do with your boat. Even the most experienced kayaker may not be in shape physically for extended trips after a long winter indoors, so you may want to take advantage of cold or rainy days to hit the gym before heading out, and build back up to longer excursions with a shorter trip or two early in the season.
Of course, you also need to make sure your boat is "in shape" too. Today's rotomolded hulls typically require very little maintenance, but should still be looked over thoroughly before the first trip of the season. Inspect the hull for cracks, deep gashes and weak spots caused by friction or impact. If there is any question about the integrity of your hull, let a professional take a look. Also inspect your deck rigging, life jacket and, especially, your paddle. You may even want to consider taking a spare paddle along on any extended trips, and it goes without saying, but I will say it anyway... always wear your lifejacket.
Although inland paddlers don't have much of an issue with currents, the rapidly changing wind patterns of March and April here can be a concern. This time of year, it's not uncommon for a paddler to start out early in the morning under calm conditions only to begin their return trip into a 15-20 MPH midday wind. And as anyone who's ever paddled into a stiff headwind will tell you, that can be a very unpleasant experience. The advantage to kayaking on our inland lakes and rivers is that you are never all that far from land and civilization, even if it's not exactly the place you want to get to. Always carry a mobile phone with you and make certain that someone on shore knows your "float plan" and potential extraction points along your intended route if weather conditions should make a return to your departure point impossible.
Even though air temperatures this time of year may be in the 70's, water temperatures, especially on the larger bodies of water like Lake Norman, will still be in the upper 50's and lower 60's for several weeks. Water temperature impacts paddlers in two ways: If you should end up in the water, you could develop hypothermia within a short period of time, and water cools the part of your boat that it touches, potentially making for a chilly and uncomfortable trip. It's a good idea to keep a spare change of clothes in a dry bag this time of year, so that if you find yourself unexpectedly wet or uncomfortable during a longer paddle, you can either change into a drier outfit or layer up for warmth. It's also a good idea to keep an "emergency kit" on board with basic first aid supplies, a couple of energy bars, a bottle of water and matches and tinder for fire-starting.