you should fix that (its a selfexplaining error please dont ask how to do that now)

wait.... you wouldn't change the 0 to a 1 because that 1 just means one pair of legs?

AddWalkerType(3, 0) -- 3x2 (3 pairs of legs)

shouldn't it be this:

AddWalkerType(3, 2) -- 3x2 (3 pairs of legs)

EDIT
and no, I dont really understand what to fix. How do I fix that?

Actually, the second number, zero, is the number of walkers of that type, which should be changed to however many you intend to use at one time. The first number of the pair is the type of walker, in this case, it's a 3, for 3 leg pairs.

The error is telling you that you're missing a closing parenthesis at line 88 in that lua, near where you loaded the speederbike.