If you need to increase MySQL Connections without MySQL restart do like below, also if you don't know configuration file, below use the mysqlworkbench or phpmyadmin or command prompt to run below queries.
mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 151 |
+-----------------+-------+
1 row in set (0.00 sec)
mysql> SET GLOBAL max_connections = 250;
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 250 |
+-----------------+-------+
1 row in set (0.00 sec)
These settings will change at MySQL Restart.
For permanent changes add below line in my.cnf and restart MySQL.
max_connections = 151