NSW — Ex-partner pregnant, I don’t want a relationship or active parenting role. What are my actual obligations and how do I protect myself?

I (30s, M) was briefly seeing someone earlier this year. We were never a good match pretty toxic dynamic, mutually agreed it wasn’t going to work. She recently told me she’s pregnant (currently a few weeks along) and has made it clear she’s keeping the baby(is a miracle coz she’s 40 and want to fix her life with the kid) and doesn’t need my involvement day-to-day she has strong family support and financial means. I have zero interest in reconciling with her or being in a relationship, and while I obviously understand I can’t stop the pregnancy, I also don’t want an active co-parenting role given how badly we get along.
Things have gotten emotionally messy a lot of back and forth over text, she’s since said she’s going to “get legal papers sorted” for me to sign and then block me out entirely she don’t want me close to her or the baby.
I haven’t signed anything and don’t plan to without a lawyer reviewing it first.
I’m on a low income (roughly $39k/year gross) and can’t afford a private family lawyer right now. My questions:
1. Child support I understand this is basically unavoidable once the baby is born regardless of relationship status or consent to the pregnancy. Is that correct in NSW/under the federal formula? Roughly how does the “self-support amount” deduction work for someone on my income?
2. Signing anything if she sends me a document to sign (informal agreement, statutory declaration, whatever), am I right that I should not sign anything without independent legal advice, even if it looks simple/favourable?
3. Binding vs Limited Child Support Agreements — from what I’ve read, a Binding agreement requires independent legal advice for both parties and is hard to overturn, while a Limited agreement doesn’t require legal advice but is easier to challenge/expires after 3 years. Is that accurate?
4. Parenting orders / custody can she (or a court) force me into an active parenting/care role if I don’t want one? My understanding is child support is compulsory but time/care arrangements are not something I can be compelled into against my will.
5. If there’s no contact for years — if she doesn’t pursue child support formally for, say, several years, does an assessment ever get backdated to the birth date, or does it generally only apply from the date an application is lodged?
6. Free legal help in NSW — has anyone used LawAccess NSW or a community legal centre (Redfern Legal Centre, Marrickville Legal Centre, etc.) for something like this? How useful/thorough was the advice for a situation like mine?
I’m not trying to avoid supporting my kid financially — I’ve accepted that part. I just want to understand my actual obligations vs. what’s being implied/threatened, and make sure I don’t sign away more than what’s legally required, or agree to something under emotional pressure that I can’t undo later.
Any pointers, especially from people who’ve been through something similar, would help a lot.