Substrate is another area worth checking line by line. Some kits include a starter bag suited to the enclosure's intended species; others include a generic substrate that may or may not suit the animal actually being kept. Hides, water dishes and basic decor are the items most likely to be missing from a kit altogether, on the assumption that a keeper will add these separately based on preference.
That distinction matters because the two things get blurred fairly often, especially by keepers newer to the hobby who search online for symptoms and end up adjusting husbandry based on guesswork rather than getting the animal seen. Reptiles are also good at masking illness until a condition is fairly advanced, which is exactly why waiting to see if something resolves on its own is rarely the safer option.
Enclosure is the more general, catch-all term that avoids the debate entirely, and it's increasingly the word used in care guidance because it doesn't imply a specific style of build. A glass-fronted wooden cabinet, a mesh-sided setup for arboreal species, and a fully planted bioactive tank could all reasonably be called an enclosure, regardless of whether someone else in the hobby would call them a vivarium or a terrarium.
Northampton Reptile Centre's care sheets set out what normal settling-in behaviour looks like for species including the Hermann's tortoise, leopard gecko, corn snake and White's tree frog, which gives a new keeper a reasonable baseline to check against during those first uncertain days. Anything that falls outside that baseline is a matter for a vet, not a matter to manage alone.
Temperature and humidity checks matter more in these first 48 hours than at almost any other point, since this is when a keeper finds out whether the vivarium set up before the animal's arrival is actually holding steady under real conditions. Checking thermostat readings against a separate thermometer, ideally at both the warm and cool ends of the enclosure,
https://www.reviews.io/company-reviews/store/reptilecentre confirms the setup is doing what it's meant to before the animal has been in it long enough for a problem to become serious.
Northampton Reptile Centre's in-store and online range lays out enclosures, heating, lighting and substrate side by side, which makes it easier to see how the pieces fit together rather than guessing from separate listings on different sites. Staff on the shop floor handle these setups day to day and can talk through what a particular species actually needs versus what's optional.