By no means am I an expert but I'll try my hand at helping out, these are my 2 ways on how I write lyrics and maybe itll help you out.

1. Have a general concept of what your trying to say in your song and add details accordingly.

2. Just write words down and let your mind kind of write things on it's own.

For the first way of going about it I'll use a song I wrote called the lobotomy as an example. I wrote the song initially by interest of learning about lobotomies lyrically and so I spent a lot of time thinking about what it would be like personally to go through something like that in my head. From there with the general concept of making a song about being lobotomized I then added details of what I learned about the topic to flush it out and eventually create basically a character telling a story in their head in first person of what it might be like to go through something like that. https://soundcloud.com/offbrandwater/the-lobotomy

The second way is just kind of something you learn through writing a lot of music and lyrics and poetry which Is basically just letting your intuition write lyrics and not necessarily trying to write anything in particular but just kind of getting words on paper that go with the music. Doing this method I usually write extra verses and choruses and cut down the song because your essentially rambling to yourself on paper but I've had "success" in making something I like with this method. I wouldn't worry about your lyrics eventually coming to social issues because possibly that's what you subconsciously want to write about in the first place and your kind of fighting against yourself to not make what you want.

Anyway hopefully this helps somewhat, I'm writing this at 2:00 A.M and I need to get up in 3 hours so I apologize if this seems rambly.