Warning: Cannot modify header information　と表示されます。

WP初心者です。

word pressのバージョンはログインできない状態で詳しく分かりません。

ロリポップからダウンロードしました。

問題のログイン画面はこちらです。
http://www.ichigo-branding.com/wp/wp-login.php

Warning: Cannot modify header information – headers already sent by (output started at /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-content/themes/-5/functions.php:10) in /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-login.php on line 362

Warning: Cannot modify header information – headers already sent by (output started at /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-content/themes/-5/functions.php:10) in /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-login.php on line 374

という表示があり、

ログインすると、

Warning: Cannot modify header information – headers already sent by (output started at /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-content/themes/-5/functions.php:10) in /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-login.php on line 362

Warning: Cannot modify header information – headers already sent by (output started at /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-content/themes/-5/functions.php:10) in /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-login.php on line 374

Warning: Cannot modify header information – headers already sent by (output started at /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-content/themes/-5/functions.php:10) in /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-includes/pluggable.php on line 680

Warning: Cannot modify header information – headers already sent by (output started at /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-content/themes/-5/functions.php:10) in /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-includes/pluggable.php on line 681

Warning: Cannot modify header information – headers already sent by (output started at /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-content/themes/-5/functions.php:10) in /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-includes/pluggable.php on line 682

Warning: Cannot modify header information – headers already sent by (output started at /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-content/themes/-5/functions.php:10) in /home/users/2/lolipop.jp-2114f9d50e462112/web/wp/wp-includes/pluggable.php on line 881

という文字がでてきます。

それ以外は、何もありません。

全くWPをいじることができなくなってしまったのですが

どのように対処したらよろしいでしょうか？

お教え頂けると嬉しいです。