How do I convert my 32 App bit to the 64 App bit to be compatible with my MAC OS?

Your very next step is to visit the application vendor's website, and see if they have a newer version of the same application than you have presently. You can also phone or email their support team, or post in their support forum to determine if the application is now 64-bit and will be compatible with macOS Catalina (10.15). You can find the vendor info usually in the About panel for the application.

For some well written vendor software, a simple recompile will be required, but others will have to decide if they want to rewrite their product, or not provide it all, for compatibility with macOS 10.15 (Catalina).

If the application is in the Mac App Store, and you have not updated it recently, then the version in the Mac App Store is now required by Apple to be 64-bit, and you should update the application from there.

If the application is from pre-subscription Adobe software versions, it may be 64-bit with 32-bit component software which will not work on macOS 10.15 (Catalina). Adobe no longer supports pre-subscription software packages. You will have to check if Photoshop Elements earlier than the 2019 version will be supported on Catalina this Fall.

If the application is from Office 2008 or 2011 for Mac, then you will need to either single-purchase Office 2019 for Mac, or start a new Office 365 subscription plan — either of which are now 64-bit.

The warning you are seeing refers to a specific app(s) on your computer that are 32 bit. This is not usually an issue with existing Operating Systems. However with the release of Mac OS 10.15 later this year, no 32 bit apps will work. To avoid issues, you could leave your computer at it’s existing Operating System. If you do decide to upgrade, you will need to determine which app is not compatible, and check with the developer of that app to see if they have, or have plans of providing a 64 bit version.

Your Mac is "up to snuff". Apple computers have been 64 bit for over a decade. It is the third party apps you are using that need updating. Neither you nor Apple can affect those app changes. The app developers need to rewrite their code for 64 bit. After the app developers rewrite their code you will have to install their new updated apps.

Maybe you could get one of your computer literate teachers or students to explain how third party apps work.

You can use Go64 to find all the 32-bit apps on your system, and then you can decide if you need to get a 64-bit version, or if you no longer need the app and can ignore it

https://www.stclairsoft.com/Go64/

Also, the warnings you are getting are so that you have lots of advance notice that if (AND ONLY IF) you upgrade to the next major release of macOS (Catalina 10.15), then these 32-bit apps will no longer work.

If you do not upgrade to Catalina, then your 32-bit apps will continue to work. Mojave 10.14 will most likely get security updates for 2 more years (as that is projecting into the future, this guess could be wrong if Apple changes their macOS support behavior).

You can't.

The app developers need to rewrite the code to make the apps 64 bit.

There is nothing you can do to make a 32 bit app into a 64 bit app.

Only the applications authors and developers can write the new code.

[Edited by Moderator]