Capital Gains

We sold our home in WA (owned for 1 year 9 months), payed cash for a truck and 5th wheel and are now living full time in our rv. We have also become SD residents. I would like to know what we can deduct, if anything, to lower the amount of capital gains tax that will be owed? I was also told by someone that we have 2 years to pay the captial gains tax owed. Is that true? And lastly how do I calculate accurately what will be owed?