Make sure that your web host has the minimum requirements to run WordPress.
You can download the latest WordPress release from WordPress.org
To use Traveler Theme please make sure that your hosting is running as the following features:
WordPress 5.2+
PHP 5.6+
MySQL 5.6+
Max_execution_time 500
Memory_limit 256M
Post_max_size 100M
Upload_max_filesize 100M
cURL: 7.4 or higher
Max_input_vars 10000
Zip Enabled
Max_allowed_packet = 128M (for database) and 10M (for PHP)