Accept this truth, we are in the internet age, even, as a dad, your uncontrolled presence on social media and internet surfing confirms this. This is not bad at all as long as your minds and brains are not controlled by the internet, and your time is not servant to the internet and social media. Some parents are addicted to it already and they are not in control. However, helping kids to maintain healthy interaction with internet is the focus here. Dads, what can we do?
Depending on your state and country, the typical minor kid age should be under 18 years old !
You are in control, not the kids !

While you should treat them with love and teach them respect, it's your house and your resource and the minor kids are under your care to guide them in the way to become useful to themselves and their generation in every possible right ways. So don't let the kids be in charge of guiding themselves, when it comes to internet usage. With love and plausible explanation with them, monitor their interaction with internet surfing and social media.
Be a good example.

The kids see how you cannot take break from social media on your social media and internet on your phones, tablets, and computers. They learn from you because you are their first trusted guardian. So take care of your self with your addiction to social media first. Control yourself time with social media and internet. You will be helping your kids too. If your work demands long interaction with computer, let them understand you are at work.
Do not ignore parental control and rules, when it comes to social media and internet for kids.

Use secured control access and implement rule on using social media and internet. Do not leave on their own while they surf through different social media etc. Monitor and see what they are viewing and storing in their brains.
Help them to use internet technology positively.

Channel their interest toward educative fun, games, good stories. With parental guidance, enhancing their educative skills through properly vented resources on internet and mobile apps may be useful for their overall learning experience. However, let them know, why they cannot go to some sites or view some violet materials, games etc.
Engage them with helpful activities offline

Set some rules on using internet and staying on online and social media. Instead, let them understand real life. Engage them with offline activities that can promote healthy growth and educative fun and learning. These could be sport camp, safe indoor games, healthy social interaction, offline book reading, healthy physical interaction with their environment etc.