Network adminstrator certifications?

Certs- Work for whatever certs are respected in your area. Look at apps, talk to people. It varies a lot. Learn how to do the tasks needed to support servers/networks. Find some older equipment/loaners and figure out what makes em tick. build em, break em and build em again. If you can show you have the knowledge, you will get a shot.

A network admin has general support of networks/servers and to some extent the apps that run on them. the focus will vary depending on the organization. A database admin is just that. They support all things related to database configuration and support. This includes cleanup, replication, deployment, etc...