Beam size advice

[Brian Brooks]

So trying to avoid the cost of a structural engineer. I am opening a 12' load bearing wall between two rooms. My house has web floor joists. The beam will hold one floor and a roof above. Below is the garage with a steel beam and has a steel pole in the center. I am trying to find the least expensive way to build the beam. I was thinking of using 2 2x10x12 with plywood in between or 3 2x10x12s. Currently it is only framed with 2x4s on 24" centers. Any advice would be appreciated.