One idea
Choose the simplest model that can answer your problem well enough. Your first ML repo is judged more on clear choices and honest testing than on a fancy algorithm.
Model families
A model family is a type of method, not one exact model. In scikit-learn, examples are LinearRegression, LogisticRegression, DecisionTreeClassifier, RandomForestClassifier, and KNeighborsClassifier.
Your choice starts with the label. If the label is a number, it is usually regression. If the label is a category like pass/fail, spam/not spam, or high/low, it is classification.