Having twins(boy & girl) need budget friendly ideals for bedding.

You will have to pick and choose on this page but Pinterest has some good suggestions for a small nursery:

https://www.pinterest.com/search/pins/?q=apartment%20nursery&rs=typed&term_meta[]=apartment%7Ctyped&term_meta[]=nursery%7Ctyped

The first thing that came to mind was a crib with storage (drawers) in it. If they are too expensive you could buy a second-hand armoire, paint it with pretty colors and arrange the inside to hold baby clothing and supplies. For colors you could go with neutral colors (green,yellow, beige, red, etc), then decorate the walls with colorful stick-on decals. Hope the babies are doing well!

https://www.youtube.com/results?search_query=crib+with+drawers

Lots of photos. Click on a photo and go to the site. Combine ideas and concepts.

https://www.google.com/search?q=ideas+for+baby+boy+and+girl+in+apartment&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiIifWW5fTaAhUn_IMKHdKYBNEQsAQIJg&biw=1093&bih=498

Maybe just do colorful accessories.... https://www.twinkledeals.com/window-treatments/butterfly-print-voile-curtain-for/p_909834.html

https://www.jcpenney.com/p/little-haven-safari-4-pc-crib-bedding-set/ppr5007699469?pTmplType=regular&country=US¤cy=USD&selectedSKUId=34256240018&selectedLotId=3425624&fromBag=true&quantity=1&utm_medium=cse&utm_source=google&utm_campaign=crib%20bedding%20sets&utm_content=34256240018&cid=cse%7Cgoogle%7C003%20-%20childrens%7Ccrib%20bedding%20sets_34256240018&gclid=CjwKCAjw8r_XBRBkEiwAjWGLlJynYhbGjZbUvLf9umFqz1_sd4IVKQHWlGsl8osb861yGhZE-3Jm4RoC7OUQAvD_BwE&kwid=productads-adid^225616513383-device^c-plaid^432398740477-sku^34256240018-adType^PLA

wall decals can be peeled off.... https://www.twinkledeals.com/nursery-decals/deals/

https://www.houzz.com/photos/baby-bedding?m_refid=olm_google_905680224_44317434679_aud-295781792330:kwd-296523331149&pos=1t3&device=c&nw=g&matchtype=e&gclid=CjwKCAjw8r_XBRBkEiwAjWGLlDGIlbbeO89WQFpj1oe2Y-9NZ6p6fb4irkJ2iCZwVh9lt2mPFzEvIBoCfOQQAvD_BwE

Hospital gift shops frequently have great handmade blankets. Contact your local quilters group to see if any of the ladies make crib blankets.

Keep it simple. Avoid used baby furniture because of recalls and safety changes all the time. Unless it's the same thing currently in the stores now, I would hesitate. Good used items like high chairs (the more modern well-balanced ones), crib sheets, clothes are usually outgrown before they wear out. Bins and baskets are easy to store things in. Keep one in each room stocked with diaper change supplies, since it will save you steps. Add color with the bedding, curtains, etc. Have a comfy chair for feeding your babies and rocking them (it's especially nice if you can put your feet up). If you haven't had a shower yet, suggest diaper cakes for the centerpieces. I made enough for all the tables for my daughter's shower, and she and my son-in-law used them for my granddaughter the whole first month. It sounds extra, but, the Godparents, and both moms went in together and bought a beautiful three shelf bookcase. We asked everyone to bring a storybook instead of a card and to write a note inside. Seven years later, my granddaughter still uses that bookcase and loves to read. We always had a huge selection of books to read to her. God bless!