help on teamfights

Hi there so im Silver V just started this season. grinded from bronze V. I usually play Jungle or Top.

so my question is that in team fights i usually try to rush their highest dmg dealers, which is usually their ADC or a really strong mage, etc.

Is this what i should be doing? sometimes it works, sometimes i die trying to rush their backline.

Should i be trying to focus their backline damage dealers or should i be trying to peel and protect for my own ADC?