Ingress is a multi-player team game. A single player can only make so much of a difference in this game, regardless of their level.
- The only way to get 4 mods on a portal is for at least two players to deploy mods on it as a single player can only deploy two mods.
- The only way to get a max-level portal is to have 8 players deploy a level 8 resonator on it as a single player can only deploy a single level 8 resonator.
- A single player can't recharge fast enough to keep a portal from being destroyed, but multiple players can keep up with the damage (lag-permitting).
The fastest way to level and the recommended way to play, at all, is as a team. In my cell, we have a few players that diligently watch the COMM for new players and invite them to a Google Hangout dedicated to helping new players level. If you haven't had anyone invite you, then I'd recommend attempting to contact an active player (whose name you see on portals nearby you) and ask them if such a Hangout exists or if they are willing to help you level.
When you first start the game, you are very incapable of doing anything. You can get AP from "dirty hacking" (hacking the portals of the opposite faction), but you take damage for every hack. You can also destroy very weak portals, deploy on already destroyed portals, or link unlinked portals, but that requires you to have very opportunistic timing.
However, if you get into a group of experienced players, they understand the importance of helping new players, especially in hostile territory. They will do the hard work for you and then let you get as much easy experience as possible until you are able to hold your own. They'll also provide you with items to help you advance for when you are on your own.
Just a few sessions with experienced players can get you leveled quickly, teach you a lot of game concepts you don't yet know, give you an idea of the history of your region in the game, introduce you to the more well-known players in the area, as well as make some connections and build friendships.
The sooner you can get in touch with other agents in your area, the sooner you'll really be playing!