Karl Marx and modern communism is a topic I am writing on, and so far this is what I have for a thesis: Marx's views and arguments that capitalism exploits working people, when re-examined in today society, do not account for the high standard of living enjoyed by a great many workers around the world, one can say economic development is best explained only by Marx labour theory of value or David Ricardo's Theory of Comparative Advantage I think it is both and thirdly, in our current time communism could never work globally but can be successful in one country. Is my thesis solid for an essay? And what could be counterarguments for each of the three arguments listed in my thesis?

This is a good start but focus on one specific point. Marxist theory is a lengthy body of thought, so don’t try to discuss all of it (or even most of it). A narrow but well-argued thesis is better than a broad one that touches on a lot of topics but can’t back up its claims.
Try selecting one aspect of Marxist theory and describe why it is not realistic. It could be Marx’s deterministic view of history, or how he describes humanity in very general terms without accounting for cultural differences between people. You can use real world examples to support your claim.
You could also select one successful communist country and discuss how its communist system aligns or deviates from Marx’s theories. It is possible that a form of communism works well but not necessarily as Marx imagined it. Alternatively, you might find one common theme in a selected group of “failed” or “failing” communist countries. Your argument would then be about a specific aspect of communism and you’d support it using those countries as examples. Some possible themes might be human rights abuses or the comparatively slower rate of technological advances. Again, remember to stick to one aspect of Marxism and use a few powerful examples rather than several weak ones.
It seems like you are also defining “success” solely according to workers’ standard of living. Your essay will need to explain why that definition of success is valid on its own (even if it seems obvious to you). One of the objections to your definition is that an increased standard of living does not necessarily mean that workers are engaged in the political process. It may mean workers have enough to eat or can purchase luxuries like a nice car, but both Marx and later Marxist thinkers such as Althusser and Gramsci would argue that these are simply distractions that allow a capitalist elite to maintain real power.
Finally, make sure to proofread your writing. This thesis statement had some grammatical errors that will only lessen the impact of your statements.

For a single essay, it is usually recommended to have a relatively narrow scope. Karl Marx was an expansive thinker and a prolific writer, so it might be useful to identify the specific works and theories from them that you plan to explore.
Similarly, specifying the time period you wish to consider will be important. Even if you limit the modern period you wish to investigate to the post-Soviet breakup, or about a thirty-year period, you will see numerous variations among nations that identify as Marxist-oriented. Even within a single country, such as Cuba, you will find numerous changes in policy and practice.
Global-scale theorizing, especially when it involves a negative proposition, is challenging to support with evidence. For an essay, two main points probably would suffice. The argument that communism could never work globally would be the most difficult to support of the three mentioned. It might be more useful to save it for a different essay and work with your refined version of the first two parts.
https://www.nytimes.com/2014/12/21/world/americas/castro-thanks-us-but-affirms-cubas-communist-rule.html

https://www.ushistory.org/gov/13b.asp