If I reset my iphone will everything be saved on icloud?

I've never save anything on icloud or backed anything up ever so I'm a bit confused. Does I cloud on a daily basis save everything from photos to notes? Without me doing anything? I'm trying to reset my phone because i dropped it and its acting weird. So I guess what I'm trying to say is, if i reset my phone is everything already save to icloud? Or was I suppose to put everything on icloud before? And if that's the case how can I reset my iphone without losing everything I haven't save?

Added (1). the thing is my phone isn't even showing anything its just lines. If Icloud doesn't restore without me saving it first how can I reset it without losing everything?

If you have opted to back up your iPhone to iCloud in Settings, then this should be the case. However, considering iCloud has limited storage, iCloud may not store everything you would want to back up. You should back up your iPhone to your computer before resetting and then restore your iPhone from that computer backup after the reset.

All purchases you have made via your *current* iCloud/iTunes account (eg music, games, etc.) will be saved.
You can restore them to your iPhone when you reset it. (that is, after you login to iTunes again)