1994 Nissan Pathfinder Rapid oil leak

I have a nissan pathfinder that has leaked oil since I bought it last year (considerable amount) I have been told lots of different things now the oil is getting an orange tint to it after its sat. We have kept up on all the oil changes. Replaced transmission fluid applied new plugs. Recently had two belts brake which we repaired now the alternator has gone out. Our check engine light never came on but once breifly three weeks ago. We need to know what it all means we have 3 small kids and are not feeling to safe with our vehicle.