can't apply for a job

Perhaps the skill category that you listed when you created your profile isn't the same category that you are using when you are looking for jobs.If that's the case, I know you can't change that category in your profile. You may want to create another profile in the correct skill category,

Search for projects, with the option "Show only projects I can apply for" checked. You will find it under the 'Settings' head (its available in right-side search options column shown while searching for projects).