The basic socialist ideas were these:

• Capitalism "alienates" workers from their lives and work.  It takes away their control over when they work and how they work.
• Capitalism takes the excess value that is created by workers and gives it to the owners of the means of production.  What that means is that it is the worker who creates the product and makes it valuable yet it is the person who owns the factory that gets most of the money that is paid ofr the product.
• Therefore, there are two classes in each capitalist society and those classes are in conflict with one another.  There are the proletariat (the workers) and the bourgeoisie (the people who own the means of production).  These classes are engaged in conflict with one another.  This conflict will be a permanent part of society until the proletariat (and this will happen inevitably) overthrow the bourgeoisie and take control of society.