You asked about the random level generation.
I use game maker studio as engine and it has some pretty good random level generation scripts. I assume you use unity, so the algorithm is the drunkard algorithm, with this algorithm you pick a random point in a map and place a floor then you choose random to go right, left or forwards and it repeats a self chosen amount, so you get a space where you walk. After that some auto tilling and enemy spawning. You can only walk on floors.
I hope you understand it. Good luck.