u/hopefulleapfailed

Hi, could anyone please help me? Could you please tell me what type of grass this is? (12 photos attached)
I have been told different types over the last few years and it has made me feel super anxious and too cautious to do anything to my lawn because I don't want to risk damaging it or making it look any worse. (I rent)
At the moment, it doesn't look like these photos because of the amount of weeds it has. I just want to be able to know what it is so I know what fertilisers, herbicides etc that I can use safely on it.
Any help is appreciated! Thank you!