Would the raspberry pi be damaged or effected at all if I simply took a usb block that you would use for a phone plugged it into the wall and used that for the power with a random micro usb cable?
3 Answers
No, it will not damage the Pi. I do it all the time. I have several 2.1A and 2.5A "wall warts" I use for the Pi, charging my phone and operating some of my Arduino units.
That said, consider the source. If the units are cheap knock-offs and heat up significantly while charging a phone, you shouldn't be using it for that or the Pi.
The phone charger will not damage your pi if it is legitimate. I did use my phone charger to power my pi until I bought a dedicated lead. The phone charger must be 2.5 Amp 5 Volt DC for the raspberry pi 3 and around 1 Amp 5 Volt for the raspberry pi zero.
Usually not but... it depends!
All "USB block" (USB power supply) has written somewhere the power rating, eg. 5V 1000 mA. If you don't find this, DO NOT USE it! Every RPi model has different power requirements, see the wikipedia page for a summary table. If you have a RPi Zero W you need al least 300 mA so you can use near all power supply and cable, also e PC port. But if you have a RPi 3B and attach some devices to USB it can draw to more than 2000 mA, in this case you need an adequate power supply AND a good quality cable.
We can divide USB cables in two groups: data cables and power cables: data cables can "transport" only 500 mA, otherwise power cables can support many Amperes. A "bad" cable can be dangerous because can melt (not often).
The Voltage of 5V pin on RPi is a good indicator if the power supply or the cable can not transfer enough current.