If you followed the SageMaker tutorial you must have trained an XGBoost model. SageMaker places the model artifacts in a bucket that you own, check the output S3 location in the AWS SageMaker console.
For more information about XGBoost you can check the AWS SageMaker documentation https://docs.aws.amazon.com/sagemaker/latest/dg/xgboost.html#xgboost-sample-notebooks and the example notebooks, e.g. https://github.com/awslabs/amazon-sagemaker-examples/blob/master/introduction_to_amazon_algorithms/xgboost_abalone/xgboost_abalone.ipynb
To consume the XGBoost artifact generated by SageMaker, check out the official documentation, which contains the following code:
# SageMaker XGBoost uses the Python pickle module to serialize/deserialize
# the model, which can be used for saving/loading the model.
# To use a model trained with SageMaker XGBoost in open source XGBoost
# Use the following Python code:
import pickle as pkl
model = pkl.load(open(model_file_path, 'rb'))
# prediction with test data
pred = model.predict(dtest)