My dad is saying pro capitalist bs

The trick is to avoid the buzzworks. Don't hit them with any words like communism, socialism, Marx, Engels, Lenin, Soviet Union, China, labour union, etc. Don't hit them with any theory either.

Just point out how the system is screwing them. Let them talk about their financial issues. Don't try putting them in a Marxist framework either. Just listen and talk about your problems too. Then ask them what they think should be done about it. THEN, you can start to:

a) either point out how close that is to Marxism (if it actually is, don't lie or manipulate obviously - but you'd be surprised how many people actually come to the same conclusions as the 2 bearded guys 200 years ago)

b) deconstruct it first and then suggest why you think Marxism offers a better solution (you should probably be prepared for pushback in this case, but as long as you keep the tones low, you'll be able to have a discussion).

Most people have been conditioned since childhood to react adversely to the buzzwords. If you mention them, you'll get eyerolls, sighs and defensiveness. If you want to go past that, you need to understand what kind of propaganda you are dealing with first and understand how to not trigger it.

For your dad's case, I'd say a good starting point would be to show him that he's not a capitalist, and will never be, no matter how hard he works.

You can't start conversations on communism by using the word communism with reactionaries who lived an entire life under anticommunist propaganda.

Assuming he makes a living as a worker and not by being a landlord or business owner, you can instead have discussions about how it's in his interest to ask for more pay for less work while the boss wants less pay and more work this creating the class conflict and how the owners of companies make billions more without working a billion times harder and that's how they exploit the worker.

You can also point out how wages stagnate and inflation increases and nobody in the gov does anything about it and yet the rich get richer. Where does the money come from, from whose value is it stolen from, ect.

Just avoid all mentions of buzzwords like capitalism, communism, ect as reactionaries have no values and operate entirely on buzzwords and what they're told is good or bad without an ounce of critical thinking.

Be patient, learn more about socialism, talk about small things in his daily life that could be improved through abolishing capitalism, like if he complains about inflations explain its causes, complains about new products being made to be broken, etc etc etc... Remind yourself that he probably has red-scare propaganda engraved in him. Also, try to not hate him, if we gave up this easily there would've been two communists in history.