No need for a watermark. Here is what you need to do for insta...
Create an account. Post content. You can link out thru the bio, DMs, and/or story post swipe up link(you need 10k followers for the latter).
Another Pro tip: When choosing your content, be mindful of what you're choosing to promote. Alot of people fail as they don't take the time to make their accounts actually look realistic. I can spot 95% of fake accounts on instagram, and thats because I worked with it for a long time. So what does that say to the users who have been on the platform for same amound of time? That they can likely spot a fake account too, maybe not as easily as me because they don't work promoting the stuff, but they've likely been fooled by one in the past and filled out a lead. These users are still good, and can still be fooled into filling out another lead. It's on you to make the account appear as realistic as possible. Skip using super models. No one is going to think that a super model wants to hook up with a random from the internet. I would advise to use realistic, everyday looking females. Post around 70% photos, 30% short videos... make use of the story, and other perks as a regular user would.
Good luck.
For linking out... always use a prelander. Direct linking will lead to fast account ban.