One of my favourite sayings is:
"How do you eat an elephant? One bite at a time..."
I've been told that one of my areas for improvement is that my ambitions sometimes exceed my reach. This is true, but that's usually by design. You never know what you are capable of unless you reach beyond your comfortable limits.
When tackling a large or complex project, my tendency is to break things down into bite-sized chunks. When looking at the whole it can be overwhelming and frightening, but when I slow it down, and break it down into manageable pieces it keeps the lizard brain fear monster back.
I can then divide my time and handle each of the pieces accordingly, find pieces to delegate or hand to others, find ways to improve efficiencies, etc.
But sometimes, we're faced with a challenge where we don't know how to break it down into pieces. This is usually one of those projects that requires a creative leap, or doing something we've not yet learned.
In those cases, just take the most obvious step in the right direction as a starting point. Sometimes it is enough to get closer so you can see your way.