Greetings, welcome to the Forums.
The photos were never posted, but all the same, some general advice can be given.
Start with observation, visit local natural areas, ones with ponds and cliffs, also visit local public gardens, and private ones too, if possible. Note which plants are growing well, and also note where and how they are growing. In a cold climate you may wish to put some plants out as colorful and intriguing annual plantings each Spring. Still, all the same, it is good to have a reliable backbone of hardy natives that will flourish and return year-after year, supplying long-term aesthetic delight and ecological benefit.