How can I make a new cutting board?

you would need a hard wood to resist splintering...I’m wondering if there would be a ready made replacement..

Maple is a common cutting board wood. I don't know if Home Depot would do it, but it can't hurt to ask. Otherwise, ask around at local lumberyards, or inquire among your friends if there's someone who does woodworking.

You can remove the cutting board for cleaning. How about flipping it over to see if that side is less worn. No matter how worn the board is, it can be sanded smooth. Then you could season the board by going over both sides with a little olive or vegetable oil. If you like the way the board looks then, reinsert it into your cabinet. If not, wipe off the oil. Drill two holes in the top edge and insert twine or wire to make a hanger. Decoupage or paint a design on the front and have a handmade

Wood holds bacteria and germs, seriously it’s as bad as using a sponge, see about getting a replacement cutting boards that are made of hard plastic.

You need a hard wood - not soft like pine. lYes HD can cut the wood for you. Most cutting boards are made from strips of wood glued together. Can you do this or are you planning on using one piece of wood?

IKEA has very serviceable cutting board countertop which can be cut to order. Asking the local big box to cut the wood is possible but they only do a 'rough cut' to size which may not be suitable. Try flipping it or sanding it as Jewell suggests. If that does not work then you need to replace. Do not be afraid to use wood cutting boards. My son in law and I argued for years and he would only use plastic. Then a survey came out that said wooden cutting boards were safer than plastic! If wood was a bad idea for hygiene purposes, then all the old butcher blocks, which we have a vintage one, in the meat stores would have been discarded by now. You do need to clean them though and retreat with oil.

You can get a used one and refinish it as well- https://www.hometalk.com/diy/decorate/rooms/how-to-restore-and-maintain-a-wood-chopping-block-44298420