You are welcome!

We can use left hand palm keys to trill from C or C# up to D! The intonation might be a little weird, but it can be a good option. For C to D, hold your C fingering and use your left index finger to trill the highest of the left palm keys (If you hold up the saxophone and look straight at the 3 palm keys, the "highest" of the 3 keys for your hand actually opens the MIDDLE pad of these 3!) For C# to D, trill the "middle" palm key--the one you would use to play a D above the staff. (This key opens the LOWEST pad of the 3 palm keys) Re: your other question, it takes time and practicing the right things! One way that I practice seamless playing from note to note is to play all of my scales slowly as a warm up. I'll pay attention to how I move my air through every note and into the next note; I check in with my finger motion (clean, precise, efficient). Next, I'll work these at a quicker speed (always with a metronome!) and strive to use my air and fingers in EXACTLY the same way even though I'm going quicker. Of course, register changes, low notes (pinky keys and voicing!), and palm keys take extra attention and are tougher to develop! Hang in there, be persistent, and know that there are no short cuts!

@@SteveBecraft I really appreciate your great advice. I am glad also concerning question 1 that someone doesn't say you can't use the palm key except with the octave key , here is an exception and the teachers on youtube should mention it that you can trill on the 2nd octave using them without the octave key.