those benches generally come with oak, but you can use teak, mahogany or ipe
I would stay away from the softwoods incase my extra large brother in law sits on it but whatever finish you use it will need to be recoated every couple of years since it will be abused by the weather
ceder. The existing wood with it's darkening grains seems like ceder. Depending on how much the wood is weathered, you could probably just sand the planks a little will be like new again. If you have a table saw and other cutting tools, then new ceder is all ya need or hardwood such as fir or walnut might look nicer. You can check with your local paint store for an outdoor stain/sealer. I did my deck with a Varathane thinking it was going to last but it didn't survive the winter. Maybe an outdoor lacquer will work for you. I know of nothing that will last. The bench may need to be touched up every year or two.
This is going to be for my 8 month year old daughter when she gets a little older. I bought it at a yardsale and wanna replace the wood but I don't kno what to replace the wood with since most of it is cracked a lot. And I was just looking for some advice on the subject of refinishing especial since it's gonna be outdoors and I don't know what kind of stain or Polly I should use
