Hi @jeanmomomo7290 
 
Which php version you are using?
 
Increase memory_limit and max_execution_time in php.ini file.
 
Or add following lines in the index.php file of the root folder.
 
ini_set("max_execution_time",0);
ini_set("memory_limit", -1);
check the following system requirement as well. 
https://devdocs.magento.com/guides/v2.3/install-gde/system-requirements-tech.html
I hope it will help you!