Anxiety

I'm having tree planting anxiety. I've wanted to plant a small tree in my small urban garden. Looking around the garden centre last weekend I found a suitable one. Bought it. It was delivered yesterday. Between those times I have spent a little bit of time looking up planting advice. I've now got the anxiety of a hypochondriac (the oh my god I've got... kind of anxiety). I have to dig a hole - I can do that, thats fine. But I do need to improve the soil it seems (general fertilizer must be bought). I need to stake the tree (do I need to get a new thicker one or is the one that came with the tree sufficient) and ties, proper tree ties manufactured specially for that purpose (so the advice says, if I can't find one, what then...). I need to water it but not drown it for the first year. Its a lot of responsibility. What if it dies? But I'm forgetting I'm quite good with plants...