Nobody knows how to make a custom home page ?

Here are a couple of related plugin tutorials:

http://learn.elgg.org/en/1.9/tutorials/hello_world.html
http://learn.elgg.org/en/1.9/tutorials/indexpage.html

Also there is a bundled plugin called "Front Page Demo" in Elgg 1.9 that can be used as an example.

Try plugins or else try php redirect code..it will work

There is a plugin called Wire Tools (https://community.elgg.org/plugins/1842667/1.9/the-wire-tools-for-elgg-19) which provides great addition to The Wire. you can use it to archive your requirement.

I believe HypeWall has that option too.

I found an issue. I have modified /mod/group/start.php next to "case 'add':"

My code :

                case 'add':
                $guidteam=elgg_get_logged_in_user_guid(); //To stock user ID
                $sql = 'SELECT * FROM elgg_entities WHERE owner_guid='.$guidteam.' AND type="group"'; //To search if this user ID own a group
                $req = mysql_query($sql) or die('Erreur SQL !<br>'.$sql.'<br>'.mysql_error()); //To execute the request
                if($data = mysql_fetch_assoc($req)) //If the user own a group
                { 
                    echo 'Vous ne pouvez pas creer plusieurs Teams'; //tell him he can't have more
                }
                else {
                    groups_handle_edit_page('add'); //Else the user doesn't own a group, he can create a group
                    }
                break;

It's simple but It's work, I am not a good developer.

You shouldn't modify that plugin directly, you can do all of the changes in your own custom plugin that won't be affected by upgrades.

Additionally you should look at the groups plugin for the correct way to get groups that user owns, there are quite a few places this is done in the plugin using elgg_get_entities

Direct sql querying is not recommended as it breaks out of the Elgg API and bypasses things like access

You're right. I'm going to find a way which respect what you say.