Hi and welcome!
First, check out this thread on how the board works. I think you have 20 minutes to modify your post, after that, editing is disabled.
How do I navigate this site?1. Is there any way to not trigger my mom when having a conversation or even trigger myself when I get upset at how the conversation is going or by the things she says?
We have communication tools and strategies that can help a great deal in terms of not escalating conflict. You can read about them here:
https://bpdfamily.com/message_board/index.php?topic=334882.0 It is hard to recommend a particular tools without knowing more details and some specifics so as you share more, we can fine tune our recommendations.

A lot of what we have to do to improve our situations is to learn to self-soothe our own difficult emotions and feelings as we interact. Managing fear, anxiety and anger will go a long way in terms of being able to have healthier interactions (for us) with our BPD loved one. I can say for sure that with time and work things do get better for us. It gets easier to manage the difficulties and our own reactions. I said easier, not easy though.

Part of this comes from learning more about the behaviors seen in the disorder and knowing what drives them to give us perspective and to de-personalize them.
part of it is learning the tools. Part of it is having realistic expectations regarding what sort of relationship we can have.
Your other question about building romantic relationships is more complex.

If looking at it from the position of having had dysfunctional parents who gave bad examples and from whom we learned bad relationship skills and coping strategies, I would say it takes a lot of self awareness and a lot of really hard work. More specifically it is hard to say without more details.
I hope to hear more from you soon.
Again,
