He's still very young and only been with you two days, he's adjusting to your environment. Right now his crate is his safe place so he likes to be in there, as he gets more comfortable around the house you should see him walking around more and interacting
Take it slow and keeps things purely positive at this stage, have lots of treats and toys at hand and play and encourage him. If you see him hesitating keep happy and stop for a moment, allow him to get his bearings and encourage him to keep moving past it. So if the stairs frighten him then take it one stair at a time and praise him for every step. He might just do one step at first, then two, but praise him either way until he gets used to them.
Same things for walks, at this age without all his shots you shouldn't be taking him all over town anyways. Take him to places where dogs rarely go or take him in your arms and allow him to experience things from there. For actual walks allow him to go at his own pace, one day you might get 10 steps, the next 20. Keep a toy and treats and make walks fun, allow him to sniff around and explore and encourage him to follow you around. Something that encourages recall is call their name and then run in the opposite direction for 10 paces, they should automatically run after you. Praise the behaviour lavishly!
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