Standard polearm tanking build:
http://aoc.yg.com/feat-planner?class...015-21,4013-21
You can adjust it for more dps, aggro etc. by moving a few points.
If you have no chance with getting raid gear (guardians have really good raid gear) then you need to farm two faction sets: one for physical bosses and one for magical (those are rare, but you will want some gear for them).
Physical set will be either Wolves' plate (the most hp and nice crit damage) or Last Legion plate (some crit chance and aggro) - best would be to mix them. For magical bosses you'll need another Last Legion set with protection.