Whats happening to my lesabre? ?

I have a 98 buick lesabre 3800. When i first start it up motor seems to stall and sounds like its not reciveing fule or air but theres also a weird noice comeing from between the engine and tranny like if gears were loose or tourque converter was spinning. Once the engine warms up a little the stall goes away and so do that horrible sound