Conversations need to end with a positive score to change the person's stats. Topics that the person likes give +2 points. Topics they ban give -5 points. All other topics are -3. This means with three topics per conversation you want two liked topics and one neutral, which is usually the one you're trying to increase. If you use a banned topic, they won't gain any points. So if you're working on Diane, it's good to do something like two chores and one social media.
She doesn't like talking about soaps because they're tagged with Romance and you haven't progressed enough for her to be okay with that. It's a banned topic and gives -5. Even with two topics she likes going with it, that still leaves you at -1, meaning the conversation is considered a failure.
A good early strategy is to just concentrate on raising your trivia score and playing video games every day until you can work as a streamer. Once you're a streamer or have another reliable source of money you can buy gifts through your computer, which are an excellent way to work on someone. Diane, for example, likes fitness magazines because they're tagged with Cheap Gift. This means you can raise her fitness stat while also gaining +2 points in the conversation. So if you wanted, you could dump two fitness magazines on her and then talk about social media and you'd get a lot of points.
As a further tip for early game, it can be useful to just talk to people as much as you possibly can because every successful conversation raises your stats in Conversation, Demonstration and Communication, which increase how fast you can increase your stats and the stats of the people you talk to. Your progress is horribly slow right now which can be frustrating but once you've talked to people enough it goes much, much faster.
Also, tip: Watch a lot of porn until you can watch incest porn, then watch incest porn a whole bunch until you've raised your skill in that up. The porn topics you get are excellent to dump on Charlie the neighbor and you need to raise your incest stat anyway.