6.
You can tell what key it is in by the starting note. Therefore, for example the first question is on "D", and it had a flat accidental. Therefore it is a Db (D flat). Now, we can use the circle of fifths
[first attachment]
to help find out where the sharps and flats fall, and since this is a major scale, the pattern is Wholestep Wholestep Halfstep Wholestep Wholestep Wholestep Halfstep (WWHWWWH).

Therefore the pattern is Dflat Eflat F Gflat Aflat Bflat C and Dflat again. You can write there as notes on the scale
[second attachment]

You can do this for the rest of question 6.

∆∆∆

7.
Just choose a key signature from the circle of fifths (an easy one is G) and put that key signature on your staff. Secondly, choose a time signature. The easiest is 4/4. If you're in "G", start in key of "G" and make a simple tune. e.g
[third attachment, scroll right]

for the other tunes, just choose different time signatures and key signatures and switch up the tune.

Hope I helped and good luck!