Danny,
It takes awhile for them to adjust to you and tank life then you still have to consider what else is in the tank, its age and its own personality.
IME, very young octos of any species will be very shy until they are about 5 months old (give or take) but older octopuses (10 months or older guestimate) placed in a tank sometime never become interactive. In most all cases, especially with nocturnals and crepuscular animals, you will need patience, luck and a lot of observation to encourage interactivity.
How are you offering food and what food are you offering? If you are not already doing so, try using a feeding stick and placing the food just outside the den at the same time every night (somewhere after 6:00 PM or if mornings are better for you to spend time with it, try early morning but be consistent). It is typical for them to try to take the stick as well as the food. I am not sure if letting them have the stick or not has any effect but you should start seeing this kind of possessive action. Eventually a captured stick will become ignored and you can retrieve it. Don't jerk the stick away and let it have it if the rock work moves but otherwise you can hold it until it is release if you wish. Once it is comfortable with stick feeding you will likely see it start to investigate the hand holding the stick. This starts with a tentative touch and release and can become aggressive. Touching the back of the arms (sometimes easier said than done) will usually get the animal to release you hand without alarming it (this only works well until it becomes accustomed to touching you but in the beginning it is pretty straight forward). They have pretty good internal time clocks and your initial goal should be to start seeing the animal come out of its den just before feeding when you walk by the tank. It will also help if you feed other things (polyps, gorgonians, serpent/brittle stars) about 15 minutes before trying to feed the octopus. If you have fish in the tank, I recommend rehoming them.