Yes, you sell your labor to the capitalist in exchange for a wage. You're required to do this in order to live, and you have no choice to pursue another path or arrangement unless you can amass a surplus of cash. Even if you can choose your employer, you cannot choose to not work, unless you have enough invested capital to live off the gains. It is extremely rare to acquire this sort of capital in the vast majority of wage positions.
May I ask what kind of work you are contracting out, and what property this work is being done at?
That wasn't me who emphasized the importance of land in the discussion and analysis of capitalism; it was Adam Smith. Land gives you the ability to charge rents, and thus not have to work for a living, provided those rents cover one's own living expenses. It also gives you the wealth arising from the Earth's natural bounty; oil and natural gas being the most prominent ones in modern society. Capitalists have to pay rent to landlords, and buy raw materials from them, while purchasing labor from workers to operate the machinery and perform various other services. Meanwhile, workers pay rent to landlords for housing while purchasing essential finished goods from capitalists. Landlords only have to pay capitalists for the finished goods, and nothing to workers. So, capitalists pay two ways while receiving money from two directions, landlords receive money from two directions while paying in only one direction, while workers must pay in two directions while only receiving money from one direction. According to Smith, this is the imbalance that is inescapable in a capitalist system.
Modern finance works in much the same way as landlords did 250 years ago, as they provide access to monetary reserves in exchange for rents (i.e. interest), and in the absence of sufficient wages being paid by capitalists to workers, requiring consumer debt, they get money from two directions while only paying it in one (to capitalists for finished goods). Technically they also give and take from landlords both for rents and land purchase financing, but that does not necessarily matter, because unencumbered title to land is almost always a better store of wealth than money. As such, they exist in parallel with landlords.
So, as a landlord and/or financier, one is only beholden to capitalists in the sense that they must be paid for providing food and finished materials to improve one's holdings. Purchasing the labor of a worker is fully at the pleasure of the landlord/financier, and wholly unnecessary if the latter does not require the services of the worker. Thus, there is far more opportunity to hoard and consolidate wealth while performing relatively little work. As mentioned before, Smith saw this as the greatest flaw in and threat to the capitalist system.
The capitalist has to pay rent and returns on financial capital (either interest or dividends), along with the wages of the worker and the cost of maintaining the capital (i.e., whatever it is that takes an input and turns it into a finished product). In return, everyone purchases the finished products or their derivatives from him. The goal of the capitalist is to amass enough profit that he can purchase title to the land, ending rent payments, while investing a significant portion profits so as to gain the advantage of collecting interest. Once this is done, the next step is to vertically integrate to reduce input costs, and then to horizontally integrate to be able to reduce output and as such inflate the price of finished products. Workers would see their wages depressed for lack of competing employers, while they would purchase increasingly expensive items on credit, provided by the capitalist. This point where the capitalist assumed the functions of landlord and financier, and then monopolized, is one of Marx's chief concerns. It is also why capitalism taken to its end is antithetical to freedom for everyone other than the capitalist, for the natural outcome is for him to control every aspect of the worker's economic life. When the capitalist has that level of control over whether the worker lives, dies from starvation, or goes into self-imposed exile, it is a despotism of the worst sort.
On the other hand, the worker must pay rent, interest on personal debt, and the price of finished goods from the capitalist, while only being paid wages. If the worker does not sell his labor to the capitalist or landlord/financier, he will be evicted, go bankrupt, and/or starve. He is not a free man, but a slave who gets to choose his master, and if he is lucky and in the right market, possibly influence his rate of pay. He has no choice that does not involve the sale of his labor for wages, and submission to the capitalist's commands while that time is paid for.
Real estate; I've done a bit of thinking on what you've stated.
I guess I'm driving the perpetual capitalist machine, with all the money I saved up on my own.