Most mixing desks will have some form of EQ on each channel strip, however this does a different job to a big 32 band outboard rack EQ. The EQ on the desk is for tightening up some ones vocal or stopping a guitar mudding up a vocal track, cutting plosives (hard P sounds) and sibilance (shhhhhhhey S sounds) etc.

A big outboard EQ will process all of the signal coming out of a desk and can be used to flatten out things like room acoustics and cut feedback.

I'd start small and learn to use the kit you have rather than going for a Porch and getting overwhelmed by all the buttons etc.

It is one thing being able to afford a PA, another to know how to put it all together and another thing entirely to learn how to use it. Start small and grow. If you don't know what something does, you probably don't need it.