I love how your style is evolving quicker than usual! Goshujin practically covered everything I spotted!
If you go to
http://www.dafont.com you can download loads of fonts all for free.
If you don't know how to install em, google is your best friend :3
All I can say is work on your linework and paneling. You had some dynamic parts which was good, but you could've made it more mint with some neat linework. The story was well executed, but somewhat of a prequel of how the two man people met and how the situation came to occur and what made everyone realize the world would cease. To make a more emotional impact in the last few panels of the first page you might want to flesh it out here and there on what caused that emotional moment.
Since you plan to start it off as a web comic, you'll only get better. Just don't bale on like I did most of my re re comics, lmao. Once you end something in a full manner you will feel alot better with your self, lmao.