Welcome to the board tinysquirrel! and congrats on the new addition to your family. I hope you find this board as helpful as I have

Everyone here is so nice and helpful
I am not quite sure what you mean by high pitched sound... but I know that some young birds, recently weaned, will make a funny noise for a feeding... maybe that is it?
As for food availability...I always make food available to my tiel... I am pretty sure that Sam posted before that most healty tiels eat what will sustain them, and won't generally overeat. I will try to find the link and post a link for you... it was just a couple days ago, and is VERY helpfu

I also think that most tiel owners here, as well as a good number of avian vets, that it is a good idea to infuse your tiel's diet with some type of pellet (though many of us agree on percentage of diet... I can also post a link for free samples) as well as have fresh fruits and veggies offered to them every day or at least several times a week. At this early stage in your tiel's life, it will be easiest to convert it to a healthy diet and get it to try new things (the older they get, the harder it becomes). Some good things to try that Bubba likes: broccoli, peas, green beans, dark leaf lettuce, parsley, cauliflower (sorry... my spelling is BAD), wheat bread, rasin bran, peppers and their seeds, apples, corn, fake crab, and just about anything he sees me eating... that is key for getting them to try new things. If you are eating it... they WANT it
You are doing well playing with your birdie... if he will let you, handle him--scratch his head, rub his beak, and let him preen you if he wants to-- that is a good bonding activity. If he preens himself on you, falls asleep on you, or grinds his beak while sitting on you, he is very content and comfortable with you. Because he is new, careful not to push him into too many things... it may sare him!! Let him be comfortable with you in his own time, and on his schedule. Play with toys with him... they don't even need to be bird toys-- Bubba loves to play with papertowels, tissues, towels, paperclips, and others like things like Q-tips.
I will look for some other "favorite" links to see what will be helpful too... if you have any particular questions... just ask
-Jackie and Bubba