Im not sure on the TC, but many first gears are not synchronized, so in most transmissions a bad clutch will definitely cause a problem with shifting into 1st. Even with a synchronized gear, a bad clutch will cause undo wear on the other synchronizers and gears. So I would definitely replace the clutch. Even if it doesn't fix your first gear, it will still save wear on tear on the transmission and probably delay the expense of a new gear box.
The good news is that you have a manual transmission. Unlike us here in the US, we can't even get a manual transmission. So when we lose a gear we are screwed!