I recommend you get a start on it and post requests for help in the regular forum area - probably "What's Wrong With My Code" - and have access to several 'mentors' who are eager to help. The app you describe is pretty typical and most who help here have done and helped with similar apps several times.
If you're specifically looking for critiques related to your coding style and techniques, be sure to mention that in your posts. With the poster's permission, more critical but helpful input regarding style and technique will be offered than most might want. We can only recommend what we've learned either as it was taught to us or as we learned through our own experiences, so recognize that what we suggest may not align completely with what might be expected of you as you continue your formal education. In cases where what we suggest differs, always do as the instructor expects.
As for where to start, I recommend you read the requirements carefully, sketch out program steps that meet those requirements (I usually use comments in a barebones program structure), and then begin filling in the commented steps with code. Some ALWAYS start a program by creating an appropriately named class with a main() method that simply prints the message, "In main() method," or something similar. You might start with something like that until you outgrow it.