Left Unity isn't about being ride or die together, it's about aligning on issues you can and discussing issues you can't. Marxists and Anarchists, for example, have a different end goal in mind. Marxists want a centrally planned, publicly owned economy with a democratically controlled government, while Anarchists want a horizontal, decentralized network of cooperatives and Mutual Aid Networks. You're going to run into disagreements, because their analysis of Capitalism has different conclusions and as such their end goals are different.
That's why we need to work together on things we do align on, like Palestinian liberation, anti-fascism, and anti-Capitalism.
We should also read more theory. Having a better understanding of our problems and how we believe they can be fixed is the key to any struggle. I keep an introductory reading list for Marxism, if anyone wants I can link it.
Here it is, Cowbee's "Read Theory, Darn It!" beginner reading list. All except one work has an audiobook alternative linked, otherwise there are text links directly to said works. It starts off with foundations, then builds on said foundations, ending with some practical advice on how to conduct yourself as a Leftist in general. I also include intersectional theory regarding trans and enby liberation, gay rights and history, and decolonialism.
Let me know if you have any questions or suggestions!