If there is an xlr on the output of your turntable, then that should do it.
Otherwise not, since it is unbalanced. Dependend in your interfaces input it might cause issue if your going form a stereo signal and line to a balanced input.
Most records are mono anyway, so i unbalanced lead outta do it as well.
Coming back to sampling, just sample every little bit you think would work in the entire track, and keep the original track as well..
Offcourse you can also flip it a bit, adjust a sample to your needs. Stretching, pitching you name it.
Laying out the samples first, in a rough way and building around it can help as well, especially if you need to switch scales, or if you need to build to entire different melody