How to plug my computer into any power source and bring my own internet?

For a couple of months, I'll be in temporary places. I'll have my Gateway mini tower with me.

How can I plug my computer into any power source and bring my own internet?

I'm thinking there's a device I can plug in and sign-in via magical sky signals. Will you give a brief rundown of how people may travel with their computer like I do without relying on in-house internet or buying a laptop or phone?

Thanks for the advice!

Added (1). I should be more clear. I can't hang out in a coffee shop or bookstore with my desktop computer.

I need to plug in at, say, a hotel room or office for a whole day.

Added (2). A mobile hotspot, aka MiFi device, is what I'm looking for. Not that I'm going to buy from AT&T, but this is what it is as an example device (in case anyone else is looking for the same thing:
https://www.att.com/...phite.html" class='ext_link'>https://www.att.com/...phite.html

Also, an excellent options guide here:
http://www.att.com/...t/planner/" class='ext_link'>http://www.att.com/...t/planner/

Again… I'm not vouching for AT&T, but their information was easiest to find and understand (esp that planner).

For a couple of months, I'll be in temporary places. I'll have my Gateway mini tower with me.

How can I plug my computer into any power source and bring my own internet?

I'm thinking there's a device I can plug in and sign-in via magical sky signals. Will you give a brief rundown of how people may travel with their computer like I do without relying on in-house internet or buying a laptop or phone?

Thanks for the advice! A mobile hotspot, aka MiFi device, is what I'm looking for. Not that I'm going to buy from AT&T, but this is what it is as an example device (in case anyone else is looking for the same thing:
https://www.att.com/shop/wireless/devices/novatelwireless/mobile-hotspot-mifi-liberate-graphite.html

Also, an excellent options guide here:
http://www.att.com/att/planner/

Again… I'm not vouching for AT&T, but their information was easiest to find and understand (esp that planner). You can get those dongles but you still must pay a service for the 3g, 4g, ect. Just like you have to for phone service. A lot of libraries and mcdonalds type places have free Wi-Fi which you can use. And libraries have sockets usually next to the desks.

If you have a cable TV service you can access the various Wi-Fi hotspots free "example Comcast Wi-Fi" you just type your account and password in and it connects you.

Last option is if you have a phone service and jailbreak you can make a hotspot on 3g-4g from your iphone and make it show as a "personal" hot spot as Wi-Fi just connect to your computer. But some phone networks will end your service or alert you that you must PAY for the service they offer to get that option. Mobile hotspot or public Wi-Fi is how most people do it.

Mobile hotspot or public Wi-Fi is how most people do it.