The tabs on the website of Smule
are quite complicated. They are made for Ocarina's at Iphone's and not for regular Ocarina's.
The Iphone can be configurated to any range and staff as needed, which means that every tab is for a particular staff/range only.
They gave the several Staffs quite remarkable names: IonianDorianPhrygianLydianMixolydianAeolianLocrianZeldarian
A tab from that site should say something like:
All I Ask of You
C 8va Zeldarian
If you want to know which tab converts to which note for this song, you have to look to the Zeldarian Fingering Chart
(for other charts, click the above links)
and look to the "Root Pitch C". And, because it says "8va" you have to raise it by an entire octave.
If the notes from the Smule-tabs are out of range for your ocarina, you can try to ignore the "C 8va" and chose another Root Pitch (This should work, but not sure).
you basicly can take any pitch you like as long as you have the right chart. But sometimes a song will a lower/higher pitch sound better.
From these notes you should be able to use the FInger COmposer
to create your new tabs.
Let me know if there are any questions/remarks.