The important parts (showing the base case and formulating the induction step) are complete! All that's left is doing some algebra, which I won't bore you with. However, if you're interested the steps are listed below:
We get n2+(2n+1)=(n+1)2 (factor out n+1 from the left hand side). So the sum of the first n+1 odd natural numbers is (n+1)2; this is the original statement but with n substituted with n+1. With the base case, the statement has been inductively proven for all natural numbers n