Take a time and look here in the Bitcointalk. There is Mining section where you can find answers for questions how and with which equipment start mining. Just stay away of cloud mining it's not fun and you will be in lost.
Most of the GUIMiner stuff will be in altcoin section. There is a lot of old stuff for it as it really is not something many do at this point. And the ones who do tend to be able to use command line at this point.
But take a look at altcoin section if you really want GUIMiner for some reason. I would suggest instead getting some USB stick miner and learn mining with it, you wont make money but good learning.