How to play a playlist I left off on?

[6+black]

I just got my first iPhone after years of being an Android user, and I'm having some trouble with playing my music. I have bluetooth in my truck and whenever I go to play music off my phone it just automatically starts playing all my songs. But I want it to just start playing a certain playlist. It sucks to have to go into my music app everytime and select my most used playlist to have it play. I keep all my genres separate in different playlists and I just want the phone to play the playlist I left off on. Instead of having to select the thing every single time. Anybody know how to fix this?