Will linear voltage regulator step up current?
No. A linear regulator works by burning off excess voltage as heat, therefore current in equals current out. The linear regulator is essentially throwing away the excess energy in order to regulate, rather than converting it to the output. You need a switching regulator if you want to take advantage of power in equals power out in order to convert a high input voltage, low input current into a lower output voltage, higher output current.

\$P_{in} = P_{out}\$

but for a linear regulator it looks like this:

\$V_{in} \times I_{in} = (V_{out} \times I_{out}) + [(V_{in} - V_{out}) \times I_{out}]\$

The last term in square brackets is the excess voltage being converted to heat. If we expand and simplify the right hand side, a bunch of things cancel out and we get:

\$V_{in} \times I_{in} = V_{in} \times I_{out}\$

Therefore:

\$I_{in} = I_{out}\$