You have now become an Eternal. Eternals are an evolutionary offshoot of humanity called Homo immortalis. This branch of humanity was created by the Celestials to be at the absolute peak of what humanity could achieve evolutionarily. They were then gifted and infused with Cosmic Energy, which gave them great powers and abilities to look after the human race throughout the ages.
As an Eternal, you are immortal and are immune to things like toxins, diseases, age etc., and have a healing ability that, should you be injured somehow, you could regenerate any injured or missing tissue as long as a significant portion of your body's molecules are not dispersed.
At your baseline with no cosmic energy, your physical capabilities are such that your strength is a match for a peak-condition Spider-Man, Luke Cage, and such. Your agility, reactions, movement, and running speeds are such that you can dodge light. Your durability is where you shine in that you can take hits from an un-angry Hulk, Hercules, and an unworthy Thor and keep on going for a few days. Your intelligence is so great that you can come up with technology millennia in advance of the modern day or pick up and master new skills in days to weeks. Your senses are superhuman, allowing you to hear in a few city blocks, smell like the greatest animals of Earth, see everything for 1 mile, etc.
And all this is without the greatest gift of the Celestials to the Eternals, Cosmic Energy, the energy of the Universe itself. With this gift, your true potential as an Eternal is realized. You can enhance all your physical abilities such that your strength can allow you to throw hands with an angry Hulk, a worthy Thor, Hercules with his godhood, an actually harm them, and if you're smart, defeat them. Your agility is such that you now view light as standing still and can fly the cosmos under your own power by manipulating gravitons around yourself. Your durability matches your strength in that it takes hits from an angry Hulk and a worthy Thor to make you bleed. Your life force is augmented by Cosmic energy, bolstering your metabolism so that you no longer get tired from any physical exertion, need to breathe, an can travel space without any equipment. Your intelligence has been enhanced such that you are capable of interpreting DNA code at a glance, accurately enough to determine parentage. You have basic cosmic awareness with a range as big as a planet, have perfect memory and indexing, such that memories are to you as 'real' as the present, with your most vivid memory dominating your perceptions. Your senses are now godly, allowing you to see through solid objects, the entire electromagnetic spectrum, telescopic vision to see objects in clear detail at long distances, even minuscule things like strands of DNA while in orbit casually, and with a bit of focus, down to the microscopic level.
This is only the basics of what cosmic energy unlocked for you. It also gave you telekinesis/molecular manipulation that at its peak can create whole ships from the molecules around you or create inviolable shields that can last for hours, telepathy to read and even manipulate the minds of others, illusions, teleportation, and the ability to manipulate cosmic energy in the form of beams from your eyes or beams, flashes, and blasts from your hands as various types of energy (gravity, various electromagnetic, quantum, etc.).
As of right now, you can only enhance yourself with the energy and do the bare basics of the above skills, like reading minds of those close by, or moving objects around a room and shooting basic cosmic energy beams from your eyes and hands. So you are given a database in your head on how to train your abilities to the highest levels that an Eternal can reach.