Usually to create database we will use DBCA graphical user interface.
Some times may not have access to a graphical user interface then we can use the DBCA silent mode to create a database.
We are going to create NON-CONTAINER database as EOPSDEV
Database Binary Version: 12.2.0.1.0
OS                     : Linux x86_64

[oracle@localhost ~]$
export ORACLE_HOME=/u01/app/oracle/product/12.2.0.1
[oracle@localhost ~]$
export PATH=$ORACLE_HOME/bin:$PATH
[oracle@localhost ~]$
which dbca
/u01/app/oracle/product/12.2.0.1/bin/dbca
[oracle@localhost ~]$


[oracle@localhost ~]$
mkdir -p /u02/oradata
[oracle@localhost ~]$
-- No need to create folder EOPSDEV, it will create automatically by dbca

[oracle@localhost ~]$
dbca -silent -createDatabase -templateName General_Purpose.dbc -gdbName EOPSDEV.localhost.com -sid EOPSDEV -sysPassword sys -systemPassword sys -emConfiguration NONE -datafileDestination /u02/oradata -storageType FS -characterSet AL32UTF8
[WARNING] [DBT-06208] The 'SYS' password entered does not conform to the Oracle recommended standards.
   CAUSE:
a. Oracle recommends that the password entered should be at least 8 characters in length, contain at least 1 uppercase character, 1 lower case character and 1 digit [0-9].
b.The password entered is a keyword that Oracle does not recommend to be used as password
   ACTION: Specify a strong password. If required refer Oracle documentation for guidelines.
[WARNING] [DBT-06208] The 'SYSTEM' password entered does not conform to the Oracle recommended standards.
   CAUSE:
a. Oracle recommends that the password entered should be at least 8 characters in length, contain at least 1 uppercase character, 1 lower case character and 1 digit [0-9].
b.The password entered is a keyword that Oracle does not recommend to be used as password
   ACTION: Specify a strong password. If required refer Oracle documentation for guidelines.
Copying database files
1% complete
2% complete
18% complete
33% complete
Creating and starting Oracle instance
35% complete
40% complete
44% complete
49% complete
50% complete
53% complete
55% complete
Completing Database Creation
56% complete
57% complete
58% complete
62% complete
65% complete
66% complete
Executing Post Configuration Actions
100% complete
Look at the log file "/u01/app/oracle/cfgtoollogs/dbca/EOPSDEV/EOPSDEV.log" for further details.
[oracle@localhost ~]$

[oracle@localhost ~]$
cat /etc/oratab | grep -i EOPSDEV
EOPSDEV:/u01/app/oracle/product/12.2.0.1:N
[oracle@localhost ~]$

[oracle@localhost ~]$
ps -ef | grep pmon
oracle    8975     1  0 08:16 ?        00:00:00 ora_pmon_
EOPSDEV <---
oracle    9865  6053  0 08:26 pts/0    00:00:00 grep pmon
[oracle@localhost ~]$

[oracle@localhost ~]$ . oraenv
ORACLE_SID = [oracle] ? EOPSDEV
The Oracle base has been set to /u01/app/oracle
[oracle@localhost ~]$

[oracle@localhost ~]$
sqlplus / as sysdba
SQL*Plus: Release 12.2.0.1.0 Production on Fri Jun 22 08:27:03 2018

Copyright (c) 1982, 2016, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL> select name,open_mode,cdb from v$database;

NAME      OPEN_MODE            CDB
--------- -------------------- ---
EOPSDEV   READ WRITE
NO <------ NON-CDB
SQL> 
SQL>
show con_name
CON_NAME
------------------------------
EOPSDEV
SQL>

SQL>
archive log list
Database log mode
No Archive Mode  <------
Automatic archival             Disabled
Archive destination            /u01/app/oracle/product/12.2.0.1/dbs/arch
Oldest online log sequence     1
Current log sequence           1
SQL>

SQL>
select name from v$datafile
UNION
select name from v$tempfile;
2    3

NAME
--------------------------------------------------------------------------------
/u02/oradata/EOPSDEV/sysaux01.dbf
/u02/oradata/EOPSDEV/system01.dbf
/u02/oradata/EOPSDEV/temp01.dbf
/u02/oradata/EOPSDEV/undotbs01.dbf
/u02/oradata/EOPSDEV/users01.dbf

SQL>

[oracle@localhost ~]$
ps -ef | grep tns
root        22     2  0 06:34 ?        00:00:00 [netns]
oracle    2946     1  0 06:35 ?        00:00:00 /u01/app/oracle/product/12.2.0.1/bin/tnslsnr
LISTENER
-inherit
oracle   10545  6053  0 08:31 pts/0    00:00:00 grep tns
[oracle@localhost ~]$
[oracle@localhost ~]$
lsnrctl status LISTENER | grep -i EOPSDEV
Service "EOPSDEV.localhost.com" has 1 instance(s).
  Instance "EOPSDEV", status READY, has 1 handler(s) for this service...
Service "EOPSDEVXDB.localhost.com" has 1 instance(s).
  Instance "EOPSDEV", status READY, has 1 handler(s) for this service...
[oracle@localhost ~]$

TNS Entry Automatically will be added to TNSNAMES.ORA

[oracle@localhost ~]$
tnsping EOPSDEV
TNS Ping Utility for Linux: Version 12.2.0.1.0 - Production on 22-JUN-2018 08:31:55

Copyright (c) 1997, 2016, Oracle.  All rights reserved.

Used parameter files:
/u01/app/oracle/product/12.2.0.1/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = EOPSDEV.localhost.com)))
OK (10 msec)
[oracle@localhost ~]$
EOPSDEV =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = EOPSDEV.localhost.com)
    )
  )
[oracle@localhost ~]$
sqlplus sys@EOPSDEV AS SYSDBA
SQL*Plus: Release 12.2.0.1.0 Production on Fri Jun 22 08:33:13 2018

Copyright (c) 1982, 2016, Oracle.  All rights reserved.

Enter password:

Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL> 
SQL>
select to_char(sysdate,'DD-MON-YYYY HH24:MI:SS') "SYSDATE" FROM DUAL;
SYSDATE
-----------------------------
22-JUN-2018 08:35:20

SQL>