I think the USSR and the People's Democracies already give a pretty good idea of how to treat certain segments of society, so my views aren't original.
>What would you do with the current upper class and ruling elites?
Following a revolution steps would immediately be taken to nationalize land and preventing money from leaving the country. The "upper class" and "ruling elites" who resort to armed resistance or sabotage will be punished either with execution or imprisonment depending on the extent of their activity.
Those who are willing to work under the dictatorship of the proletariat can be given jobs as managers, statisticians, and similar positions, providing useful work for the working-class at a time when it cannot fully staff every economic post in the country.
Depending on the state of the economy after a probable civil war which can decimate industrial production, some domestic capitalists may have their former property leased back to them for a time, though the land remains with the state and thus cannot be bought, sold or rented. The task of the capitalist would be to rehabilitate the enterprise(s) in question, and would receive compensation for doing so. Once this task was done the lease would expire or be terminated and the capitalist would cease to operate as a capitalist, the enterprise(s) in question would be integrated into the socialist economy.
>What about the fascist and liberal (SJWs) reactionaries?
Same answer as above for "upper class" and "elite" types: those who resist get repressed, those who are willing to cooperate will be integrated into the new society in some way.
Some can find employment in propaganda work, e.g. ex-fascists pointing out that communists actually defend national culture and sovereignty, liberals noting the historical democratic traditions which communists uphold, etc.
>What would be your plans for ISIS?
Assuming that a proletarian revolution somehow happened in the USA tomorrow, a struggle would be waged against the reactionary elements of the clergy in the country, whether Muslim, Catholic, Protestant, Jewish or whatever. At the same time the feeling of alienation many Muslim immigrants have would gradually be overcome, and the new foreign policy of the revolutionary government (e.g. support for Palestine, opposition to Saudi Arabia) would no longer inflame Muslim opinion abroad. The revolutionary government would not militarily intervene in the Middle East, but would support all progressive forces in the struggle against ISIS and against imperialism which is ultimately the cause of it.