Hi I'm 18, so similar age group and I have a similar outlook. Love me some 80s indie, especially the Smiths, and some post punk like Joy Division, Bauhaus etc.
Whatever you do don't default to awful 2010s singer songwriter stuff. 1. It's bloody awful - omg when people play Ed Sheeran I want to hang myself but also 2. That was all the rage a few years ago, but I'm pretty sure everyone is starting to realise how awful it is because the focus is really shifting over to EDM (I much prefer EDM as a craze because I like to dance haha). Tbh my strategy in my mind to deal with the current climate is to take some inspiration from the Smiths, because damn you can dance to their songs, but they're still interesting and indie. But I also think copying the Smiths is a bit cliche so I just try to listen to as many different genres as possible. As I said, I get a lot from post punk.
If you want some 80s indie that has more complex guitar The Smiths is definitely the way to go btw. Johnny Marr is crazy. Its jangly but very arpeggiated and turns into some pretty complex, fast riffage. Is my Smiths obsession showing? But yeah, if your playing is always just fast strumming, this sort of stuff will probably help you with giving some variation.
Other good 80s genres to try other than indie and post punk is hardcore punk. I reccomend Bad Brains and Fugazi. Also if I go from some post punk to some New Order new wave stuff I can move into electronica. They blend the two extremes well (though my fav electronica is 70s Kraftwerk and 90s The Prodigy). And go further back into the 70s and further forward into the 90s, see where it takes you. I have a record shop nearby where you can listen to random stuff before you buy it. Usually strange new indie releases. My brothers collection of old hip hop... I'm just heading into a Japanese degree, and I actually listen to a lot of Japanese stuff - Shiina Ringo (my picture is her), Number Girl, Envy. And I listen to Radio 1, I really do - as I said, I've come to enjoy EDM and maybe you could take something from it too. Just take inspiration from all sorts of stuff. Definitely don't take it as "well it's either 80s indie, or 2010s rubbishy singer songwriter stuff" - no you can take inspiration from anything and you will create your own style.
Just please please don't go bland 2010s singer songwriter style. Tbh going completely with the popular stuff out is not the way to get successful, because tastes will start to move on as you start getting places and also, you have to stand out to grab people's attention. Though listening to whats out is a good idea to make sure you have some (if vague) ties in the modern day because they say everything has to have a certain element of familiarity to be popular.