Premiere will do that for you, no need to worry. (fail safe)
1. Start a new project and name it whatever, then save.
2. When the New Sequence popup opens (it has all the presets, xcam, dvcpro, bla, bla, bla. Hit cancel.
3. Premiere opens with you’re “whatever” title. Import your footage. Drag a movie clip down and to the right, over the “new item” icon and let go. It will make a sequence for you matching you’re frame rate and size dimensions.
4. Your done thinking about ANY miss-match timeline/footage in the future.