“这段时间我不需要普通话的学习伙伴”.. maybe you just need to express your status, I suppose.

暂时不需要语伴，谢谢。

If you translate it word by word, it would be“这一次我不接受学习普通话的搭档。” but it sounds a little impolite. You can say "这一次我不需要学习普通话的搭档". It is "I don't need a Mandarin language partners at this time." in English.