I want to use wordpress themes and plugin to develop website

We can’t provide legal advice here, however publicly distributed themes and plugins should be GPL or GPL compatible, so long as you don’t violate the GPL you should be safe.

A good measure of wether a license is compatible with the GPL or not, is if it adds restrictions. If you can do it under the GPL, but not under the license, then that license is not GPL compatible.

As a side note, the branding of a plugin does not have to be GPL. If you buy gravity forms and resell it, you won’t be violating the GPL, but you will be using their logos and marketing material ( which they will be very unhappy about, and will probably send lawyers to remind you )

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)