What lenses do you have now? AF-S lenses will work on both bodies. AF-D will need to be manually focused on both bodies. There are AF-P lenses out now that wont work with the D60 and I am unsure if they will work with the D3400, perhaps someone else can chime in to clarify.
Depends on which lenses you have. The D90 has a focus motor and the D3400 doesn't. That means that older Nikkor lenses auto-focus with the D90 and those lenses won't auto-focus on the D3400
The lens I have on now Nikon DX . Under that it does state af-s. I want to get a camera that takes videos using same lens like I said before, any suggestions[FONT=Roboto, arial, sans-serif]. I'm hoping something in medium price range.[/FONT]
@Raven1
Medium price range is kind of subjective. I just confirmed the D3400 will work with af-p lenses. On the cheap, look into the af-p 18-55 and af-p 55-200. Try to get VR for both if you plan on shooting video. A step up from that would be the two lens Tamron kit, 17-35 and 35-150. The Tamron option is meant for full frame but would work great on crop sensors as well as providing a faster setup,(faster meaning more open aperture). Shooting video on a dslr does not require different lenses. If they work for stills, they work for video. The VR helps only if you plan on shooting hand held. Turn it off when using a tripod. Another option is a single lens like the 18-140 or 18-200 or 18-300 or Tamron 18-400. They all have VR, but keep in mind, sacrifices in image quality must be made for the convenience of a single super zoom.