If you use the meal plans and want to continue to use the meal plans, you can click the change button on the right side of each meal if you want to select a different meal. You can also swap out individual items by clicking on the name of a food item and then select a different item. You can also just add food items using the food search box above the Nutrition Tracker or by using the favorites tab and selecting items from there to add to your tracker. When you do that, those items will automatically be counted for your daily totals, along with any meal plan items that you have checked the boxes for. If you don't check the box for any of the meal plan items, they do not get counted toward your daily totals.
As for finding your friend, here is an FAQ that addresses that: www.sparkpeople.com/community/help_answer.
Hope that helps!