First of all, welcome to this amazing community.
The first thing you need to do is read, read and read... a lot.
The section reserved to our Samsung Galaxy S is very active and there's always something new to try.
To get rid of all that bloatware from Vodafone you need to flash a stock or a costumized ROM.
One of the most important tools that you will need is Odin. (search the forum you'll find it easily)
The first step to enter the world of costumized ROMs is the get ROOT.
There are several methods to achieve this but the one I recommend is to flash the CF-ROOT appropriate to the version installed in your phone.
With CF-ROOT you get 2 things in one step, ROOT and CWM (Clockwork Recovery Mod).
After that you can install any customized ROM, just follow the steps of the ROM Maker/Cooker.
If I helped you out, please hit the "Thanks" button!
If you need some more guidance, send me a private message.