Great to see you here. It’s entirely up to you how you wish to proceed with the mountain.
Do you have any thoughts on your approach?
Have you watched the Pile of Rocks Course ?
I would suggest starting with a primitive cone, scale up mountain sized (based on the reference, not literally mountain sized) and sculpting details like ledges and cliffs.
For now week 1 is about block out., so a basic cone and adjust the shape in edit mode to match the silhouette in the artwork, then week 2 will be sculpting and detailing.
Good luck