I inherited some badly prepared crazy paving that gets infested by weeds and grass, in fact I did'nt even realise there was a path at all when I first took it on and it was quite a task to clear it initially.
Over the years now I've learnt to keep an eye on it and tend to it before it starts to get too bad again.
I'm not a big fan of weedkillers but I do spray once a year with something containing glyphosate, which gives me a good headstart. The rest of the time, I find a stimmer is less tiring than using hand tools.
To sum up, I think it's best and Easier to get to grips with them weeds as soon as you see them coming through. Good Luck. Tbird+