Assuming you are doing extract batches, it really won't make that much of a difference. The effects of pH are highly important when doing an all grain (AG) batch, the details of which are a long explanation, so I won't get into that here. In extract, you have fully converted sugar ready to be consumed by the yeast. Where you'll need to begin worrying is first off, if your water is highly acidic or alkaline now that will affect your hop profile and if you steep the dark grains (hence lowering the pH, those grains tend to be acidic iirc) you might need to watch. But my advice would be, unless you are experiencing a problem DO NOT worry about water pH as it is quite a complicated balancing act that most wouldn't normally care to undertake. There are 'brewing salts' which are a fancy name for things like baking soda, etc. It's all chemistry. The biggest danger to adjusting with salts is that you can get residual flavors in the beer that are just terrible. The next time you bake cookies that calls for baking soda, double the amount of baking soda if you want to know what this tastes like .
Here's some good reading material: