That's two questions...
Basically, the index is laid across flat to the fingerboard. If I've interpreted the second question correctly, the index is laid completely over; it should find its position pretty naturally if your thumb is centred on the back of the neck. You'll need all the phalanges to be holding down the strings, lightly but firmly. Don't bother about other fingers until this comes naturally, and produces clean tones, every time you do it, at whatever fret (Disclaimer: it might not be so easy up around the 10th fret; no need to insist there, as it's seldom useful, especially on acoustic guitars...).
Any help..?