Hi, vcas5. Welcome to the club.
A good place to start is by
taking the test.
Can't really say about football manager, but there are several emulators / "compatibility layers", such as
Wine. There is also a wide range of software available for Linux including Audacity (an audio editor) and Muse "a MIDI/audio sequencer with recording and editing capabilities", which may meet your needs.
Most distros come with a firewall, and Ubuntu ( which doesn't) makes it easy to download and install
Firestarter. Anti-virus software is a contested issue, but the consensus seems to be that you don't actually need it in Linux as such, unless you want to ensure you don't pass on Virii to your Windows-using friends. If you wish to install it, though, there are several packages including a free version of AVG for Linux.
Email and web browsing are well catered for, and not that dissimilar to Windows apps. Many distributions will include Java, or make it easy to install (especially now that Sun has released an open-source version). There are also several 64-bit versions.
Have fun,
Rob