Welcome!
You have several good options. If you want to reclaim and use the raised bed as a garden bed rather than a pile of leaves and needles - do. But don't discard them. All organic matter will break down with time and make a great addition to your garden.
Pine needles take much longer to break down than leaves, whole leaves take longer than shredded ones, dry piles take longer than moist ones, static piles take longer than those that are turned periodically... So, give some thought to what your goal is and how much effort and space you want to devote to the project.
Creating a new compost pile and moving this material to it as your 'brown' material -layering it with 'green' material (such as lawn clippings, trimmings, etc) would be a tried and true way of moving forward. That sort of pile, in a fairly sunny spot with regular turning and (if necessary) moistening could give you great organic matter for your garden.
One thing that I once did in a similar situation when my compost piles were already at capacity and I took on a huge load of oak leaves and needles that was minimal work with good reward was to shred the material (I simply used my lawnmower), and then bagged the shredded material and stored the bags behind a shed, adding a bit of water to the contents of each bag to moisten them (which is easier done after they are moved than before). I had the luxury of time and space and after a year or so the material in the bags had broken down and was worked into normal beds.
The University of Idaho extension did a pretty comprehensive trial of compost methods and results and found that a series of three very simple 'containers' was among the best, meaning it accepted a fair amount of waste and was pretty fast to break down - all while being among the easiest/cheapest to construct. Each was built by taking an 10' length of 3' tall hardware fence (wire mesh fencing with something like a 1"x2" or 1"x3" grid, no larger or it doesn't hold materials as well), to each end of the cut wire they attached a piece of wood, then each was stood in place as a cylinder with the two wood pieces meeting, which were attached with wire loops or hooks. When in place this results in essentially a 3' x 3' cylinder. With the ideal set up of three of these cylinders you fill one, layering material, and then rather than turning the composting material you simply occasionally disconnect the wooden end pieces and fork the material from one cylinder to another which serves the purpose of turning the pile but is actually easier. The purpose of the third cylinder is to have space to add new material/build a new pile as the other is being worked. If you were to continue to add new material to a working pile you'd never get it to the point where everything was broken down enough to harvest. However, if space is limited you can get good results with only one cylinder: When it is time to 'turn' the compost, simply unwrap the wire cylinder from around its contents, set it up next to the pile and fork the material from the pile back into the cylinder.
I don't know if this makes sense - but hope it does.
Good luck - have fun with however you choose to proceed - home 'grown' compost is garden gold so don't waste it.
