I need to file end of year tax forms for a C-Corp, can you help with that?

You need to prepare the C Corp. return?  You need to use Turbo Tax Business. Turbo Tax Business  is not available to do online or on a Mac.  You can buy the Window's version here.  And you can have both TT Business and TT Home & Business (or any personal version) installed on  your computer at the same time.

https://turbotax.intuit.com/small-business-taxes

If this is your first return and you don't know what you are doing then I highly recommend you seek professional assistance so you get the return done correctly and timely and only attempt one on your own when you feel comfortable doing so.