Some tips: You're going to be given the option to trade the Spur for different weapons, I recommend you do the Machine gun first run, it's very beginner friendly. A lot of bosses have recurring attack patterns, just remember that if you're having trouble taking them down. Also, in a fight, remember that you can use your other weapons too that might be more effective than what you currently use.
I can't go over too much information to look out for without spoiling the game, so I wish you the best of luck through your playthrough.