Just got shure sm58, plug it into my starsinger on the tele but sounds is very low compared to the crappy mics? i plugged up a mixer box and can get more sound now but should it work fine with the starsinger?

The SM58 uses balanced output. If the starsinger uses a 1/4 inch jack, it is unbalanced input and probbly requires a high impedance rather than the low impedance SM58 mic. You can get an impedance transformer to fix that problem.