I completely agree ^^ Most of what I did in this jam was a first and I didn't know art or coding, but you can do anything with a bit of determination!
My advice is also like yours: plan and schedule but take your time, know your strengths and use them (for me this one is yet to be found, maybe), don't be afraid to experiment, don't judge your work too harshly, use help if you need, don't lose hope and most importantly, enjoy and have fun!
(I also never was in any team so I don't know how that would turn out, I still think I work better with others so I like to be in one someday!)