For a track bike, asusming you have 700c wheelset and tires you need a tube 18/25mm with Presta Valve

Before you buy:

Double check the depth of your rim in order to buy a tube with the valve long enough. If you buy a 60mm you won’t ever mistake but I’d rather have just a short valve coming out of the rim hole. I’m picky.

Before installation:

Remember to place the rim-tape before placing the tube. 

How to install:

Internet is plenty of instruction and I don’t want to be repetitive. Google it. My tip though is to use water in order to make them slippery to avoid punctures during installation.