Error http 500 after installation

Hallo, Im Agil From Indonesia
I use Server with detail :
PHP Version : 5.6.30
MySQL Version : 5.6.35

first time i install ojs v 3.0.2, i get error message above instalation form,

DevelopedByBlockPlugin::getSeq() should be compatible with BlockPlugin::getSeq($contextId = NULL) in /home/lppmakbidsmb/public_html/ojs/plugins/blocks/developedBy/DevelopedByBlockPlugin.inc.php on line 79

Warning: Declaration of DevelopedByBlockPlugin::getBlockContext() should be compatible with BlockPlugin::getBlockContext($contextId = NULL) in /home/lppmakbidsmb/public_html/ojs/plugins/blocks/developedBy/DevelopedByBlockPlugin.inc.php on line 79

Warning: Declaration of DevelopedByBlockPlugin::getEnabled() should be compatible with BlockPlugin::getEnabled($contextId = NULL) in /home/lppmakbidsmb/public_html/ojs/plugins/blocks/developedBy/DevelopedByBlockPlugin.inc.php on line 79

Deprecated: Non-static method Application::getName() should not be called statically in /home/lppmakbidsmb/public_html/ojs/lib/pkp/classes/install/form/InstallForm.inc.php on line 146

Deprecated: Non-static method VersionCheck::getCurrentCodeVersion() should not be called statically in /home/lppmakbidsmb/public_html/ojs/lib/pkp/classes/install/form/MaintenanceForm.inc.php on line 37

Deprecated: Non-static method Version::fromString() should not be called statically in /home/lppmakbidsmb/public_html/ojs/lib/pkp/classes/site/VersionCheck.inc.php on line 108

Deprecated: Non-static method PKPRequest::getUserVar() should not be called statically in /home/lppmakbidsmb/public_html/ojs/lib/pkp/classes/form/Form.inc.php on line 351

Deprecated: Non-static method PKPRequest::_checkThis() should not be called statically in /home/lppmakbidsmb/public_html/ojs/lib/pkp/classes/core/PKPRequest.inc.php

After that, i keep do install,
when i click "Instal Open Jurnal System’s Button, the i get
This page isn’t working

ojs.lppmakbidsuryamandiribima.org is currently unable to handle this request.
HTTP ERROR 500

after that, i see in error log file,

[24-Mar-2017 06:23:46 UTC] PHP Warning: Declaration of DevelopedByBlockPlugin::getEnabled() should be compatible with BlockPlugin::getEnabled($contextId = NULL) in /home/lppmakbidsmb/public_html/ojs/plugins/blocks/developedBy/DevelopedByBlockPlugin.inc.php on line 79

im really dont know what the problem. I hope Getting Help on this Forum, Thank you,

Hi @saferomedia

Those messages are warnings, so they should not be the problem, I think.
Maybe to somehow investigate this message further i.e. what is going on on the server:

ojs.lppmakbidsuryamandiribima.org is currently unable to handle this request.
HTTP ERROR 500

Best,
Bozana