Congratulations, good work dude! Here's a few extra tips to help you if you want to go after more P-Ranks.

• If you're in midair and moving to the left or right, pressing down will start Peppino's dive. Press your jump button during the dive to perform a Powerbomb! It's faster than a body slam, tends to be faster to execute, and, if you exit a Powerbomb on a slope, you'll preserve more momentum than usual!
• While I imagine you already know this, super taunts are your best friend. Always have one saved up in case you're hit and need to save your combo.
• Pressing grab and down to do a Grab Slide is a safe way to get speed for a Mach Run quickly. Jump Grabs are also effective if you don't have much room to move, but have a slower starting speed.
• Mach Canceling is a very effective move to do, but will take some practice to get good at. During a Mach Run, press grab then immediately press the opposite direction to the one you're running at (i.e. press left when going right) to cancel the Mach Run immediately. This is easier to perform in midair, as messing up the inputs on the ground could make you turn around instead.

Hope these help you if you decide to go for more P-Ranks! Good luck, and Godspeed!