Start with the graph of
y = x² which is this red graph:
Replace x by (x-1) getting the graph of
y = (x-1)², which is the green graph,
which you see is the red graph shifted RIGHT
by 1 unit:
Now add +3 to the right side getting
y = (x-1)²+3, which is the blue graph,
which is the green graph shifted 3 units UPWARD:
So we started with the red graph, replaced the x by (x-1) to
shift it RIGHT by 1 unit to get the green graph, and then
we added +3 to the right side to shift the green graph UP
to get the final blue graph.
Edwin