I did 4400 miles around France, Andorra, spain, Gibraltar and Portugal a few years back in the 911 on my own. I 100% took a sleeping bag, trust me you’d rather have one and not need it…
Aside from that, all you need is health insurance, breakdown cover, lots of spare fuses and spare power cables for your phone etc. Just enjoy it, long road trips on your own are ace and be prepared to adjust your route/hotels on the fly in case you fancy doing something different. Like me, when I went to Gibraltar unplanned