I'm not sure how effective those petitions are. I signed the "Repeal the NFA" petition and they are supposed to send updates within 60 days. That was probably 6 months ago when that petition ended. It has 267,000+ signatures.
If you want to feel like you've done something go ahead and sign the petition. But such petitions are not part of our legislative process. They have no legal bearing or standing. And a petition to the Whitehouse is worthless as a bill first has to pass in both houses of Congress before the President gets much say.
You want to do something let your congress critters know how you feel, except that our delegation in Utah supports such a bill so even that isn't likely to make a big difference in how they vote. So better to support lobbyist organizations such as the NRA, GOA, or SAF.
Yes I have always found it comical when associates will post a sign the petition with the beliefs that it somehow magically makes new law if 100,000+ signatures are gathered. Not saying the OP is one of these people, just stating my observations in the past.