i have several questions about tuning a trumpet:
1. so the tuner is supposed to be set to A440 correct?
2. does this mean that i have to play a concert A on the trumpet to tune or can i play any note and tune
3.which note should i tune first?
If you are using a korg-30 or something similar then you can play any note you want. The screen will display the "concert" pitch, not the pitch you are playing but it will show you how in tune you are. Yes, you should probably set it to A=440.
Many people tune different than the way they play. So try to relax and tune and play the same way. The proper sequence is to tune the open notes first. Play in the range you mostly play in. Try G and C, adjust the main tuning slide (or bell) as appropriate. Then tune the second valve on a B and F#.YOu will then tune the 1 valve (Bb, F). After you have 2 and 1 tuned you need to tune them together. Mark slide 1 and 2 with a pencil mark. Play an A (and/or E)and move the 2nd valve slide a little and the 1 valve slide twice as much.Continue until the A is in tune. Again mark the slides with a pencil. Look at the pencil marks and readjust your slides so you are half way between the pencil marks.
To tune the 3rd slide you can play G# and adjust only the 3rd slide to get it in tune.
This is the basic procedure. If you use finger combos 23 and 13 then you need to tune each mark the 3rd slide with a pencil and place the slide in the middle. If you have a slide that you can move with your finger you can set it in one position for one combo and extended out for the other. Look at what your playing and what range you are in. Tuning is a compromise so the slides will get you close to where you need to be, and you need to make small adjustments for each note. The more you play the better you get at the small fine tuning you o with your lips and throat.
Some players will tune the trumpet to the key of the piece they are playing in; but that's takes awhile to learn how to do. Over time it is a skill you can learn to use.