A lot that was similar to what's been posted: spent a lot of time outside, you either made plans in advance or you hung out in certain spots until you ran into somebody else. It really wasn't that unusual to just hang out by yourself sometimes if you didn't run into someone and just spend the time living in your imagination. In my teen years, there were certain spots like the local Sonic that you would drive by to see who was there, stop if it was people you liked or fit in with, keep driving if there wasn't anyone or people you didn't like there. I grew up in a small-ish town of 10~15K at the time in a national forest, so spent a lot of time in the woods, hiking, biking, building forts with friends, playing pine cone wars, etc. As you got older, said forts would be the hiding place for found/stolen playboys and such.
Directions from people to new places usually consisted of "go to main street, turn right at the grocery store, go two blocks, turn left, 3rd house on the left" type things. Nobody talked on the phone (guys at least) until you got a girlfriend in junior high or high school and they always wanted to talk for hours. Prank calling people with friends "do you have Prince Albert in a can? Well you better let him out!" Or getting random calls from younger girls who had a crush on you and were dared by their friends. I was laughing the other day, because I was just scrolling through Netflix over and over again and it reminded me of weekend's with my dad where we would hit the video store and walk up and down the aisles for like an hour trying to decide on a movie to rent. No rotten tomatoes or other websites with reviews and such, just had to read the back of the box and hope the description sounded like something good.
I was a

and read a lot, wasn't unusual for me to spend an entire day listening to the radio while reading LOTR's or tons of other books. If you couldn't afford to buy much music, you listened to the radio a ton. GB the day I got a cassette recorder stereo hand me down and start recording songs I liked off the radio and making mix tapes. Used to have to time it just perfectly to get your song as soon as it started and cut it off before the next song started or the stupid dj started talking. Have to listen for hours just waiting for that one song you loved to be played again to get a copy of it. I still have a bunch of old mix tapes in a box in my basement, when mp3's 1st became a thing I used to look them over in search of certain songs that I couldn't find anywhere else. Still a handful of songs on some of those that I can't find on streaming sites and such.
My mother had a modem at her work office and I convinced her to give me the security codes to the building so I could use the computer and the fledgling internet my last year in high school. I'd finish my homework or writing my paper in no time and then spend the rest of the time playing computer games or surfing for porn (just some grainy, usually scanned pic's, no video's yet.) Had one girlfriend my senior year that we would regularly "go to the movies" on Friday nights when really we were parked on some dead-end road in her station wagon. I'd look up the movie on the internet before our dates and she would tell her parents the plot when she got home so they could be sure we went.