Honestly, I don't find post-apocalyptic stories very engaging when done straight. I may be the wrong kind of reader to give you advice but I will try my best regardless.
I'm not a big fan of how so many characters were present in the first chapter. Not to mention the changes of setting within the first chapter. I understand the reasons you may have done so, but I'm not overly fond of it.
I found the dialogue and character writing just a bit rigid. I cannot find any of them likable as of yet. To be fair, In apocalyptic stories. The development never really occurs before the actual apocalypse. Hence why apocalyptic stories played straight never do it for me.
Everything just feels like filler until the apocalypse happens. I know it may be considered realistic or something but it is just not entertaining. I might be too harsh on the first episode. But I do believe that there are good stories to tell before an apocalyptic event. Some natural reactive character development will occur thanks to the apocalypse. But once they adapt, it is up to you to grow them into great, endearing characters.
I hope you can forgive my blunt opinions, it's my way of encouraging writers to grow their stories into something great and not become complacent.
+ The apocalypse you mentioned has the potential to grow some great stories
+ Solid paragraph structure
-- Weak, filler stories waiting for the apocalypse to happen.
-- Too many characters introduced, rigid character writing
-- Using a major reactive development gimmick (aka Apocalypse) may bite you in the back if you don't grow your characters enough once the initial shock of the apocalypse subsides.
In my opinion, besides surviving. Your characters should have some kind of sub-goal that does not rely on the apocalypse conflict as a crutch. So that your character does not only undergo reactive development but active development as well.
Regardless, I wish you the best of luck in your Tapas journey. If you ever get stumped, do not be afraid to get help from the community. There will be plenty of people who would love to help you out. Thank you for participating.