I have one micro SD card and would prefer to not get another one right now. I would also like to boot more then one OS. Preferably Raspbian and Ubuntu. (20 version) is there any installer software that helps with that. Any solutions will be helpful thanks in advance.
Look at Berryboot here. It has an option to make a copy of a working OS allowing you to try things and roll back if it has issues.
One thing though, any SD card is subject to failure and putting all your eggs in one basket (ok I’m a bit late for Easter) is not the best situation to be in and I would look to buy more cards maybe 16 or 32GB ones and spread your risk.