Galera Cluster with MariaDB 10 and asynchronous slave
Galera cluster auto-provisions its nodes, but that is not the case with traditional replication. You must do it manually.

Look at MariaDB documentation for setting up a slave from a backup. The process is essentially the same as doing it in MySQL, but the syntax is slightly incompatible. It usually just involves mysqldump with the --master-data and --gtid options or using  Percona Xtrabackup (these methods are handled automatically among Galera nodes).

I also include a link to the MySQL documentation on setting up a new slave because even MariaDB decided to become incompatible with it, the common explanations are way better documented than on the MariaDB wiki (e.g. using mysqldump to backup a server).