Sure there are places you can go with tables that have all the tools and piles of shrubbery, but - in my opinion - finding your own way (and stumbling a bit) is so much more fun! I especially love trampling through the forest/garden to find clippings, gathering twigs etc and finding other winter treasures (like the glowing orange fungi below!!!)
Anyhoo, below are some clues for wreath-making from this non-professional. Good luck and have fun on your adventure!!