Transmission fluid

Yes so if it shows on the low side on the stick, you'll be safe to take it for a easy drive to warm it up and circulate the fluid and recheck it again when you park. Just keep the motor running when you check it.

It is a 4L60E , thank you both.

5 quarts for a 4l60e if you just drop the pan and change the filter

The GM service manual states an "approximate capacity", for pan and filter removal 5 quarts. I've done many of these, and found it to be just over 4.5 quarts. 5 quarts, always left it in a slightly overfilled condition. It's better to start with 4.5 quarts, and add as needed. Easier to add/top-off, than to try to drain excess fluid. If someone put a deeper aftermarket pan on, could be even more than 5.

How many do I put in it after replacing the transmission

If added too much transmission fluid, how do I drain it out?

To drain, use a long hose about 7/16 outer diameter and 5/16 inner diameter, stick it down the dipstick tube, then siphon it out - be careful, up to about 3 quarts could be drained in this manner. Just keep pushing it in til it stops BTW. I recommend siphon pump on a drill to avoid knowing taste of tranny fluid