I feel for you, been there done that. This hobby is measured in months, not days or weeks.
Study your snails' and hermit crabs' behaviour for a month. Feed them no more than twice a week. They might appear to be simple creatures, but watching them is fascinating.
Add some LR
, a handfull of snails, a hermit or two, let them settle in for a couple of weeks.
Splash out on a couple of shrimps. Watch their antics.
Maybe after 3 months consider a fish or two.
Any faster than that and you'll be disappointed.