Yeah, good point - the half-stop close to the nut can be initially difficult.   Yup.   Keep to the two middle strings and play a D minor (natural) - D E F G A Bb C D

Keep at it until it "sounds right" to your ear.....   then you have that 'half step away from the nut" on the Bb on the A string

I initially found that difficult, simply because of my hold.   A little bit of practice soon relaxed that "death-grip" in the early days, and it becomes easy...  I think the "tight hold" on the neck because you think you're gonna drop the instrument is, or can be, half the battle making it hard to get that "half-step" just above the nut ( well, it was for me )

Once you have that - it becomes easier on all the other strings.   All other half-steps (a finger "low" or "high" if that's your preference ) on the neck are a different issue, and just have to be learned ( your ear will tell you ) 

Same old, same old, 2, 2, 1, 2, 2, 2, 1 for a major scale, and, 2, 1, 2, 2, 1, 2, 2 for a minor.   So why did I pick D minor here to talk about ?  Because if you can play D minor, you can already play F major ( a key with one flat - namely Bb )  - instead of the scale D E F G A Bb C D, you play the SAME NOTES but start at F.  

F maj is F G A Bb C D E F

Wooo - easy - huh ?   LOL