first off welcome, and a good way to answer your questions before posting is the check out the search function and the caresheets.
>40 gal is way too big, you wont need one that big for a couple years, at your size you will be just fine with a 20gal.
>a heat lamp and an UTH are a priority unless you plan on using heat tape or a snake room. this is covered in the caresheets. you need to have a warm and cool side because snakes are cold blooded and by having a warm and cool side in their enclosure they can thermoregulate their bodies, this way they dont cook or freeze. hot side should be around 90 and cool side 80. also you will want to get two hides, one for each side.
>letting them get used to a new environment is good so they can adjust and have some time to calm down. most of the time it will stay in its hides, even after the week, so dont plan on it cruising around alot. If it does cruise it could mean its hungry or nice and comfy.
>as i mentioned before a 20gal will be just fine, and a bigger enclosure wont be necesary for awhile. if you have to big of an enclosure your bp could get stressed, and not feel secure enough because its such a large area and its such a small animal. making your bp feel secure is key.
>as for names, that is completely up to you. why not taz?