In all actuality it could be very dangerous. While we ourselves would love no know that we are not alone, and would like to believe that others would be more benevolent, it is just as likely that they would find us delicious, or cheap labor or not even consider us worth the time of day.
Our hope of course is that it would be a cooperatively mutual learning experience. However, anyone that can travel or at least communicate over the vast distances of space (in a timely manor) would most likely be studying us as we study the great Apes.
In all actuality, even though in theory our radio waves will travel across the cosmos, some of our earliest broadcasts reaching 110 light years away, it appears that outside of a couple light years away that our signals are indistinguishable from background radiation.
The reverse would be true as well, so sending us a message would be a major feat in itself. Hopefully, they would send the instructions on how to reply. Now if they are actually traveling around the galaxy that is a whole other jump.
Why do they want to communicate with us? What do we have that they need/want? If they are not benevolent or curious, then they want something from us or our planet.
If it's benevolence we are golden, (mostly) they will try to help us reach our potential, but they also might try to train us a pets to follow some path that they have mapped out for 'our own good'.
The curious, would be looking for knowledge, and this could work out for us too, becoming more knowledgeable about the universe and advanced sciences. Though, Mengele was curious and wanted to learn about us and performed experiments, learning many useful things about humans. It didn't end so well for most of his subjects however.
If we have anything aliens want, if they can make it here, they can just take it and we couldn't put up much of a fight. But they might want to have a trade outpost and find it easier to have us prepare what they want and just arrange shipping. Like how we use places like the Philippians or Chinese factories. Cheap labors, the locals are 'happy' to have a 'good' job and the aliens make huge profits.
The last, conquerors. If they want the planet for themselves, they just might wipe us out, or keep enough around to act as slaves for ruling elite. Best might be for us to be 'conquered' (mostly just saying we now belong to them) and integrated into their society and economy, like the Romans used to do. We become a secondary citizen in an interplanetary system that has rules we can learn (and manipulate, it's what we do) with both expectations from us as a vassal planet but with an overlord expected to protect us from attacks from other hostile societies.
So in my estimation, it's about 50/50 whether things are worth it to make contact, do it benefit or hinder the development and growth of a civilization. The best of all worlds is to be either the first one to be out there, or to get the technology to observe any other intelligence that might be out there and to study it and possible reactions it may have about contact.