[Nealtw]

Better would be to stop short of the side wall and build the wall on top of the block facing the outside and you can attach the first stud to the block and tie it together with the top plate. I would go with the peel and stick tape flashing. You will need a primer for the block wall.
That header should have 2 stud each end. If the width isn't important you could add it down to the floor.

 

[Nealtw]

If you were building a house you would probably want 2 jack studs on each side. Since it is a shed its probably okay the way you have it. I think code is 1 jack stud for 2x6 spanning up to 5'5". Since this is just a shed i wouldn't worry too much about it unless you have massive snow loads. As for sealing that off I don't know the best way. If I was doing it I would try to get it as straight as possible with grout/stucco before putting the wall up then seal it with a tube of silicon

Check you code again, 2x10 double header needs two jacks at each end at 60" or more.

 

[Nealtw]

Thank you for the replies. I drew up a sketch and took a screenshot of the model I made in Sketchup which should give a better visual. Since the there is a partition wall and all 3 walls are not perfectly lined up I chose to put the framing in front of all of the block instead of having the walls between as you suggested Nealtw. That way I will have a continuous and straight exterior.

The block wall faces are not perfectly straight. and in order to get the front wall plumb the bottom of the framing at each of the end walls is separated by ~.5-1" from the block. I am trying to find the best way to seal this and make the transition between the 2 materials. It is a shed so it does not have to be perfect.

Nealtw, To clarify are you saying I should have 2 jack studs + a king stud? I am putting a sliding door over this opening so the opening width does not matter too much. This is my first experience framing so I am learning from research online and the projects I looked at with similar sized doors only have 1 jack stud. Would the reason for 2 be the length of the opening?

Thank you again for the help!

2 jacks for 60" and more

The wall we can see where you have it on top the wall. I would have cut that at your last full length stud. On top of the wall the bottom plate would have gone the other way, in line with the front of the big wall and bumped into the block wall. Then install a stud and nail it to the block and the second stud goes at the front lined up with the big wall. Tie it together with the second top plate overlap.

 

[Nealtw]

What?

It the code that i was talking about. That is a span table.