Crossing a major road? Afraid? Help!?

I'm going over my friends house later today and we really want to do this art project together, but we don't have the supplies. She said we would walk to the walmart that's right near her development. But to get there, we'd have to cross and walk along a major road with like 6 lanes of traffic going different ways.

I mean, they have crosswalks and she said she's done it before but I have crossing even tiny roads, and I'm just terrified to cross a major one. I'm just afraid of getting hit by a car or my best friend getting hit or getting taken away...

But I'm sure I'll have to cross a road like this some time in my lifetime, and I'm trying to convince myself that I'll have to get over this fear sooner or later.

Oh and we're both 16 year old girls. And I'd be doing this without my mom knowing. She would never let me and she won't drive me to get the supplies. So what should I do? Get over my fear and cross/walk along the road or no?