Everything that gives you AP in Ingress involves portals. So you are correct in that Ingress will be very dull without them around you. With that said, you can make some portal suggestions around your home and in a couple of months they may or may not be online without Niantic really telling you why.
XM is different from AP. XM works similar to stamina in other games. You need XM to perform actions on a portal. You have an XM bar, and you fill it up. The only downside to your XM bar depleting is that you will be unable to interact with portals until you have sufficient XM again. Portals deposit XM on a regular basis and because of this you usually will not have to worry about XM until at least level 4-5.
AP is experience. AP is gained from interacting with portals so to answer your original question, you are absolutely dead in the water until you get out and start hacking some portals downtown. Once you acquire a portal key you can recharge the portal remotely for a hot 10AP at a time which will never be worth it unless you are trying to keep a portal alive. You can see the amount of AP you have by tapping on your level at the top left and looking below the XM bar.
Below is a table for AP values for interacting with portals.
- Placing a resonator 125 AP
- Recharging a resonator 10AP
- Destroying a resonator 75 AP
- Placing the first resonator on a portal 500 AP
- Placing the eighth resonator on a portal 250 AP
- Creating a link 313 AP
- Destroying a link 187 AP
- Creating a control field 1250 AP
- Destroying a control field 750 AP
- Applying a portal shield 150 AP
- Placing the final link on a field 1563 AP
- Destroying a [full] portal 600 AP
- Destroying a portal + (1) link 787 AP
- Destroying a portal + (2) links + control field 1724 AP
- Destroying a portal + links + cf + capture + mods 3524 AP
This is the amount of AP you need to level up in total AP needed.
- 1 - 0
- 2 - 10,000
- 3 - 30,000 (20,000 from L2 - L3)
- 4 - 70,000
- 5 - 150,000
- 6 - 300,000
- 7 - 600,000
- 8 - 1,200,000