"I tried to sleep but it was very noisy."
Translation:Я пробовал спать, но было очень шумно.
If you're referring to пробовал and пробовала, they're both acceptable because it depends on the gender of the speaker (which DL doesn't know).
If the speaker is female then пробовала would be correct.
If the speaker is male then пробовал would be correct.
Well, we can't tell you that without knowing what they were. Do you remember?