I totally get it, and you are not alone - I think most people 'wait' to learn how to use their powerful cameras!
If I may suggest, put the camera on the tripod, set the dial to A-DEP (automatic depth of field) and then set the Exposure control (usually a range of -2 to +2 on that camera) to -2 and start with that. You might need to then move up a bit on the exposure level the other way, depending on the flower etc.
The A-DEP will help make a maximum depth of field, set the F-stop and shutter speed where it needs to be, and the exposure control will compensate for a small bright image with a mostly very black background.
From there, play around with it!
If you don't have a remote control, I'd suggest one of those too:
Amazon.com: Canon Remote Switch RS60 E3: Camera & Photo
Once you start with those settings, you will see what the camera is settings things at, and you can then take more control and adjust it.
Hope that helps some!