While you may be able to make the new pump work with some reworking of the plumbing and electrical, it's not nearly the pump your old pump was. I would suggest sending it back if you can and getting a pump with closer specs to the original.
Do you have any water features that require the larger pump (i.e. waterfall, fountain, slide, etc.)?
If you really want to use the new one you'll have to at very least change the breaker that feeds the pump, and re-identify the wires. Then you'll either need to add a receptacle and box or replace the cord with hardwiring.
Do you have any other equipment that is powered by that same breaker (i.e. swg, timer, etc.)?