I am not an expert in soil modeling, but I did find a few articles on the Internet (1) (2).
What results do you want from your model?
Are the static loads on the pile cap vertically downward?
Are you modeling a single pile or a group of piles connected to a cap?
Are the piles supported at the bottom on bedrock or only soil?
Are you going to have different layers of soil properties?
Is the cap above the soil or in the soil?
Are you on a Student license or a full license? The Student license has a limit of < 32,000 nodes+elements which will make it difficult to build a continuum model, but you can easily build a beam model with nonlinear springs to represent the soil, however, that was in paper (1) that was studying earthquake ground motion causing inertial side loads on the structure.
The procedure if you use beam models is to create a beam for the pile with the correct cross-section and material properties and attach springs. The procedure if you use a continuum model is you create a block and a pile, subtract the pile from the block, share topology and assign materials to the pile and soil.
If you go with a continuum model, ANSYS provides a list of Geomechanical material models, some of which are appropriate for soil modeling.