Q1: You can have only one ASM instance per node, you find out its name in the same way that you would for a non-RAC environment.
Q2: Connect, using operating system authentication, exactly as you would for a single instance database.
Can you explain your situation? It sounds as though you are not familiar with Oracle at all, never mind RAC.
1) If you have n nodes, you will have n ASM instances and db instances. Coz for each and every node one ASm and one db instances will be running. And if you want to know the name of each ASM instances,
First go to grid_home/bin and execute ./olsnodes -n --> to find out the hostnames and hostnumber in your cluster.
eg: let us take 2 node rac as example.
Now we got the hostname and its number in the cluster
Then again from grid_home/bin, execute
./srvctl status asm -n <hostname> ---> this command will show the asm instance name and its status on the particular node
2) Say for example if your database name is ORCL, then ORCL1 is the db instance name on the first node, ORCL2 is the db instance name on the second node and so on............
No matter how many nodes you have, the database name is common. ie ORCL. You would've configured this ORCL database entry in your client tnsentry.
so Just export ORACLE_SID and connect it as you would connect to normal database. you will be connected then.
Hope this would've cleared your queries.!!