In general, all businesses that perform a service or engage in a trade for profit in Nevada are required to obtain a State Business License. There are some exceptions. In addition county or municipal licenses may also be required. An EIN number is a Federal requirement and may or may not be necessary depending on many individual circumstances of your LLC.
Purely passive entities that engage in no business within the state may not need a business license - however if the LLC is holding assets with the intent of selling for profit then it is a different story. The cost of a business license is minimal to the headaches that can be caused by failing to follow the regulations.
Please see an attorney in your area for an analysis of your facts to the relevant law. The foregoing is general information only, not specific legal advice. No attorney/client relation has been created or should be implied.