Welcome to the site !!
Oil is a "user" choice for the most part , the things you do need to worry about is whether it meets the standards that the engine needs to run well and last , especially for the clutch , as it needs a wet clutch compatible oil or you will fry it
Generally speaking , Motorcycle Specific oils are highly recommended , but i have used Shell Rotella (Blue bottle full synthetic) in my bikes without issues as it meets the JASA and MA standards that these bikes need to run
I just switched to Maxima (full synthetic) in my 450R because i am at the track a lot with it and like how it shifts better/smoother than with the Rotella , , but i am still using the Rotella in my 06 450X , that said , as mentioned , do your research , but i would not recommend just grabbing any automotive oil and putting it in your engine and transmission (oil is separate for engine and tranny on the X , but you can use the same oil type/weight in both sides , i would recommend running a Full Quart in the tranny side , and use the recommended amount in the engine side)
As for Coolant , again , you need a coolant that will work with Aluminum engine and radiators , so again , i personally would recommend a motorcycle specific coolant , i personally use "Engine Ice" , it raises the overheating temp and its made to work in our bikes , where i live we get 20 below zero to 110 above temps , and i have had less issues with overheating and evaporation since switching to the Engine Ice
Hope that helped some
