You gain pvp points as you rank up. You rank up by pvping. You're correct that frontlines is your best bet to learn, try asking around to learn the prime times to queue for your data center.
As for your abilities, you can use all of them even without allocating points into them. Take the time to read the tooltips for them, usually they are pretty valuable abilities.
The rest is just practice, play around and do your best, learn from mistakes and try to have fun.
You can go to Wolves Den Pier and use the pvp only abilities on the training dummies on top of the boat to get an idea on what they do.