Sometimes you just need to scratch that middle-of-the-night online shopping itch, so: here's some ideas based on your baby's very basic sleep needs:
Somewhere for baby to sleep, or safely be put down when necessary e.g a cot or moses basket - preferably a couple (with at least one being easily portable) so there is a safe sleep space in each room.
A mattress for each sleep space - Infant sleep spaces should come with appropriately fitted, firm mattresses. Second-Hand ones are not recommended. A firm mattress is necessary to reduce the risk of your little one sinking into a soft space and their breathing being compromised.
Fitted sheets for the mattresses
Suitably firm mattress for any sleep space - incuding yours if planning on co-sleeping!
Sleeping bags of various togs (aka thicknesses) - smaller number 'tog' means a thinner material so more suited for warmer temperatures, whereas a larger 'tog' means a thicker sleeping bag so better for the winter months. It is recommended that, if concerned your baby is too cold, you dress them in multiple light layers that can be easily removed if their temperature begins to increase as opposed to fewer thicker items.
Swaddles (if this is something you'd rather use until baby can roll…). My personal favourite (so far) is the Love to Dream swaddle sacks as they keep baby snug while respecting babies natural tendency to want their hands up by their face!
Night Light - with light on the red spectrum rather than blue or white as red has less of an impact on sleepy hormones at night so you don't wake up too much!
Important: Products advertised for babies as helping them sleep for longer, or deeper are not recommended as safe. Babies have evolved to sleep lightly so as to wake when something internally or externally puts them in danger!
I offer a range of guidance for new parents, including tailored advice and hands on support.