Dare I ask which camera store and what you were phoning about? If they're being a pain in the proverbial then take your business elsewhere. You'll probably find everything is cheaper online but it can be a good idea to go into a shop and actually have a look at the camera and see if you like it.
As for tripods it really depends on what you're likely to be taking pictures of. I wouldn't think it's a "must have". Looking at your original post the first thing you mention is action photography and a tripod would be more of a hinderance than a help there. It probably wouldn't fit in your rucksack either (although it depends on what tripod and how big your rucksack is!).
A tripod really comes into it's own when you're shooting in low light or doing things like multi-shot panoramas or HDR.
Places like Jessops *sharp intake of breath* do sell cheap tripods for around £20 or £30 but I was never very impressed with mine and barely used it. I've now got a much better one and it gets a lot more use but then I have a much heavier and larger camera, and carry around a lot more gear.
As for courses it really depends on how serious about photography you are. I've never been on one and (at the moment at least) have no inention of signing up for one. I found that most of the information I've ever needed has been easily available on the net or via a forum like this.
There is a lot of jargon and a lot of terms which don't make sense to start off with but reading magazines, forums and other websites answered all of my questions. I even found I learnt a lot from reading the in depth camera and lens reviews on
DPReview. Their blogs are pretty good too for some of the more technical things.
If you're after a camera that you can learn with the Canon would certainly be better than your current one as you have the PSAM modes (or P, Tv, Av and M as Canon call them). Everyone is different and courses work for some people and not for others but I've found that I've learnt the most be going out and taking pictures. Also, I've spent so long in lectures and Universities that I'm sick of classes!!
There are some very good books which might help. Bryan Petersons book
Understanding Exposure is about £12 and explains a lot in simple terms, mostly relating to perspective, metering and stops.
In short, there is no right or wrong answer here but I would recommend seeing how you get on with the camera and if you want to learn more or not. You never know, you might get bitten by the bug and be wandering around with a big SLR and several lenses in a couple of years or you might still have your bridge camera 5 years down the line but give yourself a chance to try it before you throw all your money into it.
I started off with a predecessor to the SX120 IS (the Powershot S3 IS) and bought an SLR within a year as I was thoroughly addicted but I'm glad I started with my S3 and gave myself the opportunity to see.