What I cannot view the data even when I have select_catalog_role

I am connecting to Oracle 12c R2 database instance. My account has select_catalog_role privilege. I can view schema definitions of any schema in the database,

but when I try to look at data, it gives me error. that table/view does not exist. why. .e.h,

select count(*) from testchema.table1

ORA-00942 table or view does not exsit.

But when I do

select count(*) from dba_users

I get a count.

What privileges are needed to view the data. I do not wnat the ability to update data, just view data. Why I can voew data from dba_suers but not for a user schema..