Take what you have, start small and learn from it.
Old laptops are great, because they have low power consumption and even pretty used up battery will give you power redundancy.
Even a 10yo laptop is something with 4-5th gen Core cpu and that has plenty of power to get you started.
Well it's nice not to have a speed limit, but every time I see one, it's such a sigh of relief.
Story time:
Not so long ago, I was on that 4 or 5 lane autobahn before arriving to Munich. I was already dark, overtaking some car, leaving the most left line empty. Then these laser high beams basically illuminating the nearby Alps. I was thinking geez I'm doing 160, relax dude, you have a free lane here. I moved to the right, 2 lanes to my left are now free. Car flies by me, doing probably like 50-70 more than I, AND, AND this guy gets overtaken by another one with about the same speed difference relative to the guy doing 210-230.