Hello Mariah,
You have similar gear to me.
I recently shot a conference with about 250 people attending. I thought my shots we OK.
I just bought a Speedlight 430 ex 11 and it made all the difference, especially with the 50mm 1.8
Cheers and good luck
John W
__________________
John
Sydney Australia
Canon 7D, Canon EOS 450D, Canon EFS 18-55, Canon EF 100-300 f5.6, Canon EF 50 f1.8 11; Canon Speedlite 430 EX11, Fuji FinePix F40
and now with new and improved Canon EF-S 18-135mm f/3.5-5.6 IS, Sigma 18-200mm F3.5-6.3 DC and Mamiya ZE-2 35-70mm F3.5-4.5 Macro