Transmission Trouble?

[91 Supra]

Hey guys! I am a newb to the forum and was looking for some help in troubleshooting the problem that my supra is going through. I have a 91 Turbo 7M-GTE AUTOMATIC TRANS, 86,168 original miles that is almost bone stock[Ive only added a FIPK Air intake and decent cat back exhaust] Here's the deal, on cold starts, the car will not shift normally. It will usually just kind of skip through 1st gear while the rpms continue to go up[at which point, i let off the gas] I have to ease the car slowly for it to shift[It shifts rather rough though] After about maybe 5 minutes of easing through the gears, the car finally begins to shift nicely at about 2000 rmps for the 1st gear and so on for the rest of the gears. Ive checked the transmission fluid and the dipstick reads perfectly and the fluid is not burnt. It does not leak any fluid anywhere so as a novice in the realm of auto mechanics, Im kind of lost here. Any expertise on the matter would be greatly appreciated. Thanks for your time guys, I look forward to reading your replys.