Do you have any resources or advice around allowing a newborn to sleep on the chest of a parent? And around cannabis use whilst caring for a newborn? (Including breastfeeding) Thank you.

Red Nose recommends that the safest place for baby to sleep is in a cot that meets the mandatory Australian Standards.
Baby should always be placed on their back for sleep on a firm, flat (not elevated) &well;-fitting mattress.

Red Nose has the following information in relation to sleeping baby on parents chest.
This position tho’, can cause baby’s chin falling to their own chest, with the risk of compromising baby’s airway.

Sleeping baby on the parent’s chest
Sleeping baby on their tummy on the parent’s chest, often skin to skin, is an excellent strategy for settling an infant, and can help them self-regulate their temperature, as long as the baby and their airway are being observed (either by the nursing parent or another adult care-giver).
A parent falling asleep with a baby prone (on the tummy) on the parent’s chest and unobserved can be problematic as prone positioning reduces baby’s arousal mechanisms that protect baby’s airway; baby’s nose may become obstructed by clothing, or parent’s body or breast; or an unobserved baby may become positioned with his/her chin to chest, which will also obstruct baby’s airway
Download Sharing a Sleep Surface With a Baby

This can also happen in some devices, not recommended for sleep, like a bouncinette.
When a baby falls asleep in a propped up device the head can fall forwards, pushing the chin
down towards the chest. This can lead to the airway becoming blocked and reducing airflow.

Tilt your own head forward and place your chin on your chest. Try to breathe through your nose. Can you breathe freely? No. Babies breathe better when they are lying on their back on a firm, well fitting, flat (not tilted or elevated) mattress.
https://rednose.org.au/article/bouncinette