Do Sims need to get to level 10 in a skill for challenges to show?

Check the skills in the Sims skill panel. Each individual skill will have different challenges that require different levels of skills or different achievements to complete. For example when a sim knows 28 recipes that will complete a skill challenge. Making 25 ice sculptures will complete another skill challenge and that sim will then be able to make ice sculptures that never melt. Each skill has one or more challenges.