Learning scales may not seem as interesting as playing melodies, but a little effort at this stage will pay off later on, regardless of the style of music you play. Write out the remaining major scales with the appropriate key signatures, using eighth notes as demonstrated below.
Memorize the notes of each scale and then try playing it with your eyes closed, while imagining how the notation would look. Once you have learnt all the scales, you will be able to read music better, play melodies confidently in any key and be able to improvise in any key much more easily.