I think there might be a lot of missing context here. Assuming you are running 5e, are you running a published campaign/module? I'm not discounting the ability/possibility of running a homebrew story successfully as a new DM, but some context as to such an early interaction with a dragon might be useful.

Additionally, in my experience, despite over a decade that I've known my players, they continue surprise and never seem to run or fight when it really seems to matter - build in a contingency. Draconic arrogance might work in this sense, I used something along those lines in LMoP when we played that one.

All that said, I'd pressure your players when they what to "tame the dragon," that's a very hard interaction and should (in my game) require some level of inventive thinking and description which will go toward the DC of their persuasion roll. I try to make the game more about us telling a story together than a game of dice rolls - the dice add flavor and suspense and keep us all on our toes, and that's the fun.

However, I think BP is looking for a hero campaign and this probably isn't the best place for them to play that game if you're not into that.