Turned out that the inability to deploy the 8th resonator was a bug - I wish I'd taken a screenshot. When I got back to my computer, I looked and 8 had been deployed. It must have been I kept tapping deploy on my phone faster than something could handle it, and it just didn't show up. I'm wondering if restarting the ingress app on my phone would have fixed the issue as well.
As far as being unable to link it could have been for a number or reasons that I didn't know at the time. Portals link distance is determined by the level of it's resonators, and I may not have had sufficient resonators.
Level Range
1 160m
2 2.560km
3 12.96km
4 40.96km
5 100km
6 207.36km
7 384.16km
8 655.36km
It also could have been because the link I was trying to create crossed the link between some other portals. It wasn't obvious to me that this wasn't possible at first, but makes sense and you get a message telling you why you can't link to a portal if you click confirm even though it's greyed out.
Finally, it could have been because portals only allow a certain number of links. You can only have 8 outgoing links and 8 incoming links. When this happens you'll see something like "Origin Link Capacity Reached" when you try to confirm a link to an unlinkable portal.
You should be able to grind your level up to 2 pretty easily just by hacking enemy portals for 100 AP each time, which is tedious, but past that you're going to have trouble and get bored with 100 AP at a time. Here's a list of things that earn AP - I know most of it is impossible to do at low levels.
You're really not going to be able to do much solo at low levels, so the best option I can think of when you're starting out low level and at a team disadvantage in your area is to organize your local faction and destroy enemy portals in groups. Get at least a couple other people together and attack an enemy portal that is well linked (you'll get more AP for destroying links and fields), low energy and in a location that will allow you to link to the few portals you do control (you get even more AP for creating links and fields than destroying them). It might be hard to find the combo of the those, so take what you can get, but work together.
If you can't find people local at a higher level to help, you might try asking high level players from neighboring towns. Some people are pretty into this game and will take long field trips to help take over outlying regions.
If your opposition isn't very active, you can let your portals decay so that your links and fields disappear, and then relink for a bunch of points.
Finally, a couple options that requires vigilance:
Submit portal suggestions and check to see if they or other portals in your area get added, then be the first to them when they do. You'll need to check http://www.ingress.com/intel and zoom in until it says "Showing all Portals" to be able to see the new portals when they're added.
Another option is to watch your email like a hawk for portal destruction notifications when the enemy destroy a few of your resonators on the few fields you do control, then as with the decaying strategy mentioned before, swoop in and recharge, redeploy and relink your portals. You can do the recharging from a distance if you have the portal key, which will buy you some time to get there to redeploy and relink. I find it helps to leave one low level resonator in an easy to destroy location (like on the sidewalk), and try to place a least one higher level resonator in a hard destroy location (like inside a building). Then you should get notified of the lower level resonator getting destroyed hopefully before they can get to the higher level one.
Best Answer
Hack plenty of enemy portals. You get 100 AP for hacking an enemy portal, but none for hacking a friendly one.
If there are no unclaimed portals around (highly likely in some locations), find a level 1 enemy portal and start slugging away. You'll want a few dozen XMP bursters at minimum to destroy the portal, but the rewards are high--destroying 8 resonators and planting 8 of your own on a single portal will get you almost a quarter of the way there. Even if you don't manage to capture the whole portal, you'll still have gotten 75 AP for each resonator you destroy.
Deploying portal shields is a good way to get AP that may not be obvious at first. Check every friendly portal you encounter to see if it has a full complement of shields. If it doesn't, deploy as many as you can. You get 150 AP for each one.