I'm really not being facetious is saying this, but you need to take as much time as it takes for your mouth and tongue to heal completely.
You might want to pick up some Biotene (there are some different formulas, so read the labels at the pharmacy). Many find Biotene to help a lot.
While you're abstaining, muse about your unfortunate experience. Think about your pipe, you tobacco, how you prepare the tobacco, how you pack it, light it, your smoking style, the pace of your puffing.
As you ponder these things, first is to zero in on your condition: Was it bite or burn? Burn is caused by steam, such as condensation of moist tobacco, sometimes mixed with saliva, that, when heated by the tobacco's burning in the pipe, causes steam and burns the crap out of your mouth and/or tongue. Tongue bite can be caused by a number of factors -- maybe the tobacco blend does not agree with you, a physical reaction. Another cause of tongue bite is puffing to quickly and/or too often -- virginia blends are a good example -- some blends absolutely demand respect and solid technique, so will either reward you for doing it right, or punish you severely for "not getting it." Either condition can easily sneak up on you and the resultant "oh sh!t" moment not realized until it's too late.
Was your pipe completely dry and clean before you fired it up? I should have been.
Did you properly prepare your tobacco? Correct cut/consistency, allowing for proper dryness, for example.
How's you're packing technique? Too loose, it will burn too fast and hot. Too tight, it will be difficult to smoke and burn unevenly. The draw should be like sipping soda through a straw; if the draw is like sipping a milkshake, your packing is too tight. The tobacco in the filled bowl should be "springy." As you practice this, think looser than tighter.
Charring light, while puffing, then tamp the tobacco evenly prior to the true light. Puff slowly, then slow down some more. Sip. If the tobacco goes out, tamp, relight, sip, sip, sip.
Good luck! Remember that patience is the hardest think to learn for a new pipe smoker and patience touches every aspect of the hobby. Good luck -- and let us know how you make out!