My green thumb???

It's beginning to dawn on me that my green thumb is a healthy shade of mediocrity.
I am aware of the obstacles against me. The weeds were allowed to rule my yard without question for many a year. The Virginia Creeper was encouraged to climb almost as high as our roof and make not so subtle attempts to creep inside our siding. The back yard was the very large toilet of a healthy chocolate lab. This, I was prepared for.
I am still sad that my Bleeding Heart seems to have bled to death. What the heck, all the research I did on this thing stated that Bleeding Hearts were foolproof. Don't I feel foolish.
I don't understand why I can get Edelweiss to grow and not poppies.
Why why why did the previous owner think yarrow was pretty? Now it's all over my front grass.
All the other hollyhocks I've seen have flowers by now. Somehow, mine are stunted. At this rate, I will have hollyhocks blooming for Labour Day.
My healthiest plants are petunias, impatients and pansies. These are happy little flowers. I'm thankful that they have the grace to grow in my yard despite the heat and my inexperience.
What do I do? I think I will continue to water my blooming mess, learn from my mistakes and try again next year.