In my back garden (which the previous house owner completely neglected). I've planted lots of roots for Asitlbe, some peonies (but the roots I bought were seriously dried out and probably just dead now that I think of it - serves me right for buying from a junk store), and there are some hostas already growing. However I didn't plan well. I buried the astilbe and peony roots and don't know what the sprouts look like, nor do I have specific markers for burial (I just have a good idea of where the hole is, but not where the sprout would be).

This problem is exacerbated by the fact that tons of weeds are making their way in from the brush behind the garden (like I said previous owner didn't take care of it). I can't tell what are astilbe and peony sprouts and what are weeds. I've included pictures. Please help me know which ones to kill!

Pic 1 overall garden (it has these obnoxious trees that send out shoots of small saplings under the ground it seems, and they are nearly impossible to get rid of. any ideas on stopping them from sending up new shoots? I don't want to remove the grown trees themselves).

Pic 2, possibly a sprout?? It's a lighter green color and I don't see any more of these in the garden. Index finger for scale

Pic 3 larger "twiggy" sprout or weed, about 3 in tall

Pic 5, these are everywhere. I assume they're weeds

Pic 6, this is a top view of a plant directly in between both the grown trees. It's about 5 inches tall and has been there for a few months wit little change. Is this a weed or a plant?

thank you everyone in advance. Next year I will put down that anti-weed fabric and cut out holes where the real plants will come up to avoid this much confusion!