Selling you're soul to Satan is not hard, and OP is right; he and other entities are eagerly waiting to connect with you. He will appear to you in some way, shape or form. He'll give you what you want in exchange for your soul, but you best believe their's going to be a catch, for that he never negotiates outside of his favor.
And for the record, no I have not sold my soul, or practiced satanism. I don't fukk with black magick, or the like because there is a HUGE karmic backlash from that shyt. On top of having a near spiritual attack. I've experienced more than enough paranormal events to understand that there is something greater than us humans, and the what we see and experience here in the physical world. Some things aren't to be toyed with.
I have a pretty extensive understanding of this stuff breh so let me share what I know.
Satan as a creature, is not a "fallen angel", he was created from a different substance than the angels and is a totally different species.
You're right that we are not alone on Earth. There are things that our instruments of perception simply cannot perceive. Some call them "spirits". They're basically a creation, similar to us in many ways, yet also very different.
They have different "ethnic groups", different sub-species even, different languages, religions etc..
They can perceive us but we cannot perceive them.
Some of them are undoubtedly good, but those who are good rarely come into contact with humans because they are not supposed to.
Those who do come into contact with us usually do so for sinister reasons. They generally do not like humans and look down on us. They are also, generally speaking, less intelligent. If you look into Alastair Crowley, you will find that he was disappointed in his communications with these spirits and found them to be brutish and unsophisticated.
They also vary in strength. The strongest amongst them usually become the leaders and they subjugate lesser ones and dominate them.
Satan rebelled against God in the heavenly realm and was cast down to earth. He was envious of God's love of mankind since he perceived himself to be more worthy of love due to his status and essence. Those from amongst those "spirits" who follow Satan are what we call "devils". They are literally the embodiment of pure evil and there is literally no good in them. They worship Satan.
What black magicians do is that they usually submit to a leader from amongst the devils They sacrifice to him, commit all kinds of filthy acts to draw nearer to him. When that devil is satisfied with him, he will assign some lesser devils to go do some work for that magician. This will last for a certain amount of time until that devil gets tired of that magician and demands some even more degrading acts from that magician. shyt like taking his own children to the desert and performing sexual acts on them. Drinking menstrual blood etc..
They will also make the magician call other ppl towards blasphemy. So when you go to a magician, he will usually ask you to sacrifice some animal while reciting certain names. Those names are the names of devils. Sacrificing animals for other than God is blasphemy.
This is why magicians usually reside in filthy places and have a sinister, filthy look. If you've meet one, you'll immediately sense that there is something off about him.
Reflect on the stupidity of thinking that you can "control" something that you cannot even see. The magicians are the servants in that relationship not the Masters.
I realize this was a bit of a disjointed rant, but feel free to ask and I will explain some more. A lot of these rituals that people perform have specific meanings that most of you do not realize.