New to TomTom and need help

Hi, I don`t really know a lot about GPS, but I`m keen to get mine working properly. I have a Tungton T3 which I recently bought with TomTom Navigator installed. Don`t know what version it is. When I`m using it, I have realised it must be quite an old version as I keep on driving through fields ( new roads have been built ). I want to update to new maps etc so bought a TomTom Go vesion 5 sd card. Needless to say, when i insert the card, nothing happens.
This is now going to show how much help I need. Do I take it GO is not compatable with my T3 with navigator installed ? Can I wipe the card and copy my navigator on to it ( the nav is 128, the new sd is 256 )
Can I use the SD card for other things ( ie camera)
From reading threads, can I download Navigator 3 / 5 onto my old card ( 128mb) or can I donload it onto my GO 256 card ?
Sorry if this isn`t making sense, but I`m getting pretty stressed out witrh the matter.
Please help, I need it

[Charlie]

Welcome to our forums.
You seem to be in a bit of a mess. You cannot use the GO SD card with yout T3/TT kit. You can wipe the card and put your standard TomTom on it but I'd recommend returng the GO SD card for a refund if you can. You can use the card in other devices although I'd recommend you don't if you plan on using it for TomTom. If you buy TT3 you will only get the software on CD and will need to install the maps from it on to a card. If you buy TT5 it comes on its own SD card and you need not load it onto anything else.