I agree with everything said so far.By 'set up' I usually look
at the height of the strings above the fretboard at the NUT
end (just below the tuners,where the fretboard starts) and
then at the BRIDGE (or SADDLE if your ukulele has one)
Lower at the NUT first,and usually that is all you need to do.
If Not,a little saddle lowering may be required.Plenty of threads
about that if you search on here!
Then strings,are a personal choice.If you start with cheap
laminate model,most recommend AQUILA nylgut strings,as
they 'drive' the soundboard better.That is,they make the
top surface of the ukulele vibrate more,and sound louder
and,usually,better.Sharp fret ends either side of the fret
board can be cured,again,plenty has been said in the past,
use the SEARCH function.Simply 'set up' your instrument to
suit YOU,so that it is comfortable to fret (finger) and strum,
Musical Intonation is okay right across the scale,(you will
hardly ever get it perfect,if you use an electronic tuner.
That's another issue,called Compensation,which you will
also find threads about!).Remember,one persons 'perfect'
set up may not suit another.Just get it comfortable so that
YOU enjoy playing it,and in tune!