I think my biggest suggestion might be to try to avoid the huge industry of companies selling "makerspace" stuff to libraries, i.e. GlowForge, etc. All of it is wildly overpriced and underpowered, at the supposed tradeoff of having a lot of support. It's a bad trade, the support isn't worth it.

Try to build your own open source equipment, like Voron for 3d printing, OpenFlexure for microscopes, all the Precious Plastics designs for plastic scrap processing, etc. Building these from scratch is ultimately cheaper. Also, it means you'll know how to fix anything that could possibly go wrong, since you know it inside and out

Don't worry about not having the necessary skills/experience. It's all very learnable by anyone, and also there are definitely members of your community with those skills willing to help out. On that note, you really want the community running this thing more than the library admin. They know what they want/need.

Pay attention to the environmental and health consequences of this stuff EARLY ON, before you invest in something terrible. Use easily compostable materials like PHA and hempwood, or post-consumer recycled stuff like PETg from used soda bottles. Get into making/recycling your own materials if/when you can.

That's what i can think of for now, hopefully that's at all helpful.