Two frame rates in one project

I have a drone that shoots 30 fps maximum at 2.7k. Fine for the aerial stuff but I want to combine it with handheld footage that I’d like to shoot at 60 fps so I can do some slow motion. Is it possible to put these both in the same project? If so, how?

You can set the timeline to your target resolution and add clips into it to your hearts delight. They'll get adapted and you can choose the method for that, best is optical flow.
For time-lapse, go the Clip Attributes and conform to the target speed.