Julian said it best, so I ditto what he said.
You'll want to decide on your track table size asap, though. unless your garage is 12'+ high, you won't be able to hinge down an 8' wide table. 5' wide is plenty, really, especially if you go 16' long. You can then design a track to fit the space. Base it on plastic sections, but go crazy with the different radius turns, because routed lets you do anything. Then, you can adjust the routed lines to be more like a racing line than following the edge of the track exactly all around like plastic does. Put lane changers at the end of straights on the entry to turns, and they'll work great.
But yeah, if you're not already sure, then take it a little slower. With a little TLC, I bet your old track will work fine. Check out the Track Maintenance articles in the Slot Forum Resources page if you need help.

You'll want to decide on your track table size asap, though. unless your garage is 12'+ high, you won't be able to hinge down an 8' wide table. 5' wide is plenty, really, especially if you go 16' long. You can then design a track to fit the space. Base it on plastic sections, but go crazy with the different radius turns, because routed lets you do anything. Then, you can adjust the routed lines to be more like a racing line than following the edge of the track exactly all around like plastic does. Put lane changers at the end of straights on the entry to turns, and they'll work great.
But yeah, if you're not already sure, then take it a little slower. With a little TLC, I bet your old track will work fine. Check out the Track Maintenance articles in the Slot Forum Resources page if you need help.