Hey Fallows,
Your tank looks really good! For shrimp, they love heavily planted tanks, so if you can get tons of plants and make the tank super heavily planted in an arrangement too that would be awesome. How did you plant the java fern? Java fern as a rhizome (thick root part where all leaves are attached too) that HAS to be above your substrate or it will die. That's why most people like to tie it onto rocks/driftwood.
I seriously recommend getting a test kit. It'll be hard to know when to do water changes, to determine why things are dying etc. The $30 for a liquid test kit are well worth it.
There are other options for a palladium too. You could do salamanders, fire belly toads (Cool little guys!), tree frogs, and a lot more animals I don't know of lol. Do some research, but if your heart is set on shrimp then that would work perfectly fine in this setup!