George is simply after the American Dream. Freedom and being able to become your own boss and have your own land is what he desires.
Lennie is set on tending the rabbits, and defending them from the cats that dare threaten them. Lennie is dependent on George, so what George wants, Lennie wants too, to keep George happy.
Candy doesn't want to become useless on the ranch, because he knows that once he can't work, he won't be able to gain work because he is handicapped and no one will want to hire him. On the ranch, he can do odd jobs, like washing dishes etc, where he'll still be useful.
Crooks, strangely it would seem, wants to work for George for free. He'd still be doing slave labour like he does on the ranch and without money. But on George's land, Crooks would get something he could never get on the ranch; respect.
Crooks wants to join George, Lennie, and Candy's plan to buy a farm because he is tired of being isolated due to his race and wants a sense of belonging. Additionally, he sees the opportunity to escape the oppressive and discriminatory environment of the ranch, where he is marginalized.
Crooks rescinds his offer to join George, Lennie, and Candy on the farm because he realizes that it was unlikely to materialize after Curley's wife threatens to have him lynched for suggesting he had a right to refuse entry into his room. Crooks also realizes he will always be seen as less than the others because of his race and decides it's safer to distance himself from the possibility of a better future.
Join Lennie and George's dream
Crooks offers to join Lennie and Candy in their dream of owning a piece of land and working for themselves in exchange for being allowed to work on that land with them. He wants to feel included and not left out due to his race and isolation on the ranch.
He wishes to join Lennie and George in "their dream" of buying their own ranch.
George is afraid to have Candy overhear his plans for the farm and his dream to join Lennie in owning rabbits. He worries that Candy will judge him or interfere with his aspirations.
Crooks is initially skeptical of George and Lennie's dream of owning land because he has seen many other ranch workers with similar dreams fail to achieve them. However, he becomes more hopeful when he sees how much the dream means to George and Lennie, and he eventually offers to contribute his own savings to help them achieve it.
Crooks offers George and Lennie to join in on his dream of buying a piece of land and living off the land independently. He allows them to imagine a future where they can escape the hardships of their current circumstances and find a sense of purpose and stability.
Candy is enthusiastic and eager to join George and Lennie's dream of owning a piece of land, seeing it as an opportunity for a better life. In contrast, Crooks is initially skeptical and cynical about the dream, feeling excluded due to his race and social status. However, he eventually warms up to the idea of joining them after feeling the hope and companionship that the dream represents.
I think it was Candy, wanting to join in at the ranch and pay for half of the cost of the ranch.
Curley's wife and Crooks, two cynics, scoff at the dream of Lennie and George as being unrealistic, but Candy sees its possibility and its beauty. He offers to give his life savings to help make the dream a reality, for he wants to join George and Lennie on the farm, living out his last days in happiness. when the two men accept Candy, he suddenly has a new lease on life; the dream has given him hope for a better future.
Candy offers George and Lennie money to help them buy the land they dream of owning. Candy is desperate to join them in their dream of owning a piece of land and is willing to contribute financially to make it a reality. He sees this as an opportunity to have a sense of belonging and security in his old age.
In Of Mice and Men, George is noted from the start as the sharp, practical one of the two. When Candy tells George that has the savings to join in the plan, George says that he will consider it but makes Candy promise to keep it secret, so George, Lennie, and Candy make a pact to keep their dream to themselves.