Shrimp require a diet filled with nutrients and minerals to help them molt and a lot of this can be free in the form of Spinach, Kale and other green vegetables, the only issue with this is that unless you are buying or growing your own organic plants is can be quite dangerous for us to give or shrimp any fruit or vegetable bought from a store, most of them will have been sprayed with pesticides that stay in the plant for months and months.
This is where buying pre made shrimp food from a trusted source makes life easy for you.
I personally make all my own food with only organic natural ingredients.
Which can be found here
Make sure when you are starting out that you can get yourself a good 3d printed shrimp net, you can use the old type fish nets but they have been know to catch shrimp legs and damage the animals and break legs and anttenna.
Now this just depends on your budgets and what you can afford, sponge filters have been the mainstay in shrimp keeping for years and with good reason, they provide good filtration and help move the surface of the water which is good for Oxygen exchange, they also have an added benefit in that the shrimp love to graze on the sponge.
I myself prefer a sponge filter attached to a small power head this is only for personal preference as I like have my shrimp room as silent as possible as its in my house. for this I use the Pat Mini Filter
Reverse Osmosis Unit:
This is where you can really take of with your shrimp keeping as a reverse osmosis unit will provide you with the ability to make your water any way you like, for more in detail information look here
Here is a cheap unit that wont break the bank