I think they "green lighted" you. My gym does it. When some one comes in saying they want to fight they grind them into the ground. If they are seriously giving you this chance and you are serious about wanting it. Suck it the hell up. You went from zero to 100 in a week...or how ever long....Like voiceless said you should have prepared a lil before but oh well too late now. Plus it wouldn't matter if you prepared or not they would wear your ass out.
Now just because you are sore don't mean shit. Do not go into the gym and complain. If you complain they will throw more at you.They are trying to break you. They want to see how bad you want this....the question is.....How bad do you want it
Credit to M.C !!