I want to move to a different area but have been unable to sell the home I have now. I am 75. Can I use the money in my 404K to buy a new house while I continue to try to sell the one I am in now?

Do you owe anything on your current home.
Next why is it not selling, how long has it been on the market

And will you have enough money to live on if you never sell the other house ?

Yes - you can withdraw as much of your 401(k) as you'd like, to do whatever you'd like. But be aware that you will owe ordinary income tax (both federal and state/local, if applicable where you live) on whatever amount you withdraw.