If strange symbols are displayed on your website, it's related to incorrect database and/or page encoding. In order to fix this issue, page encoding needs to be changed. Your website should also have UTF-8 meta tag:
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
You may also try to add this line at the top of your index.php page:
header('Content-Type: text/html; charset=utf-8');
Also, there could be a problem if your files are encoded in "UFT8 with BOM" support. You should open these files on your computer and encode them in "UFT8 without BOM" support. And then upload files again. You can change file encoding with software such as Notepad++.