Assuming I'm at home when it starts.
Part 1: The panic. I'll wait out the first 3 days in my house, this is what I'll do right at the beginning.
A) Barricades: My door is located in a narrow hallway, so I'll simply put my fridge in front of it as an easy and quick barricade, it's pretty heavy on it's own but to be safe I'll stash it with books for added weight (I have lots of books). I'll keep the food that stays good for the next 3 days (I'll get to why soon) and throw out the rest. My windows aren't a problem, I live one floor up (about 10-12 foot off the ground), I'll close all the blinds so my flat doesn't attract any attention, I have double glazed windows so it's pretty sound proof, but I'll keep quiet just in case.
B) Food and water: Fill my bathtub and all bottles I have with water before it shuts off, this gives me a good supply for 3 days and more. As for food, I've always got a good supply of canned/dry food lying around, and I've got the food in the fridge that doesn't go off for 3 days.
C) The wait: I'll wait out the original panic, if the military/government takes care of it after 3 days, then great, I'm saved. If not, I'll prepare for part 2.
Part 2: Survival pack, Meeting with friends and finding a place to stay.
A) Preperation: The panic is over, my supplies are running low and I need to meetup with my friend (he's part of my plan, we've discussed it). This first thing I do is get put on some bite-proof, long-lasting clothes. This includes jeans, a jumper, a jean jacket (or any other strong material) etc. Then I set up my bag, I'll put three days worth of food and water inside, 2 extra pairs of socks and undies, a survival knife, a torch, about 10 AA batteries, 2 boxes of matches, a small mirror (for signaling) and a basic first aid kit. I have all this stuff in my house at all times. In my hand I'll have my weapon(s), primary is a hammer, secondary is a kitchen knife, I know they aren't the greatest weapons, but it's the best I got, I'll avoid combat for as long as I can. I keep the keys to my house, I can go back there for a change of clothes and for emergency shelter, I'll also need stay there for a few more days (I'll explain why in B).
B) Getting out: First thing I do is look outside, if there is loads of clutter and destruction on the street, I'll go by foot, if not, I'll take my bike. The meeting place with my friend is my school gate, I can walk there in 15 minutes, jog there in 5, so getting there is easy. We've agreed to meet there every day at 2PM after the first 3 days of panic, I'll climb the school gate and wait for him inside there until 4PM, then go home before dark. If he doesn't show up in 3 days, I assume he's dead or un-dead, I'm on my own. 3 days is the limit as by then all my food and water will be running out, and I'll need to move on. Let's assume he shows up, I've got my bag with a few supplies, my weapons, he's got his. What's next?
C) finding a place to stay (short term): We have a few options here, I'll list them with there pros(+) and cons(-):
- My apartment: + easily protected, only need to barricade the door + balcony, for storage - small - need to frequently leave for supplies
- Detached houses near school: + well protected, many have 7 ft metal/brick fences sorrounding the house + large - need to frequently leave for supplies
- "Yellow shop" (it's a corner shop/conveniance store) and flat above: + very well protected, the shop has no windows, one door which has a metal shutter + massive amount of canned/dry food and water (and alcohol), could easily feed 4 people for 6 months if rationed. + large
The ideal place would be the Yellow shop, if we don't get it for whatever reason, we'll have to scavenge and loot other shops for food and water and bring it back to out hideout, to bring things back, we'll use a small suitcase if on foot. Sleeping area will be any bedroom or lounge, toilet will be in a plastic bag and then thrown far out the window and we'll piss off the balcony (all locations have balconies). We "shower" in the rain (it's England) and leave our clothes out in the rain for a basic clean. Rain may also be collected for drinking water. Another thing we will loot is libraries. Books for not only entertainment, but education. Survival, medication, science and driving are all topics we'll need to read up on, and for our long term plan, we'll need to learn how to pretty much run a farm and hunt, and 6 months is a long time to learn all these things. A survival pack (backpack) will be ready at all times in case we need to leave imediatly for whatever reason. Hopefully we'll pick up more survivors along the way, preferably good looking women ;) (4 more people maximum)
Part 3: Finding a place to stay (long term): After up to 6 months of being in the inner city to suburbs transition zone of London, it's time to leave. Food and water is running out or going off. Our safehouse is getting crowded with the addition of a few more survivors (if that happens). We need a long term safe zone where we can live sustainably.
A) Preperation: First thing to do is to get a vehicle. This will be either a large SUV or a large van. We may have to siphon petrol and hotwire it (we'll learn how over the 6 months of reading). Add basic protection to side and back windows. Make sure we have a repair kit for a flat tire, an extra battery, enough petrol to keep us going for a week, enough food and water for 3-4 days and our survival packs. We'll take a few books for entertainment, maps and books on hunting, farming, fishing, survival, medication etc. We do this with one vehicle if there is up to 3 of us, if there's 6 people (maximum) we'll to the same to another van/SUV.
B) Getting out of London: We'll take out vehicle(s) down south, to the coast. Find a fenced farm with a nearby river (upper course of the river) or a well and a good amount of land. At this new location we'll be able to get more people in our group if we find people. Maximum is raised from 6 to 12. We then live off the land and repopulate.
I've thought about this quite a lot ;)