fragments, run-ons, and comma splices

All his life, however, McLurkin has enjoyed building things
As a child, he played for hours with legos and cardboard boxes, like many future engineers, he wanted to understand how things worked.

You might want to stop after bulding things, before starting with as a child, "All his life, however, Mclurkin enjoyed building things."

But Im not convinced at what you would like me to revise?

All his life, McLurkin has enjoyed building things - you don't need however here

As a child, he played for hours with legos and cardbaord boxes. Like many future engineers, he wanted to understand how things worked. you don't link 2 independent clauses together with a comma; that is a comma splice error.

If you want to link them, here is the revised version

As a child, he played with legos and cardboard boxes for hours because he wanted to understand how things worked, like many future engineers.