I am new to Numbers. Have made SIMPLE spreadsheets in Excel for years. How/Where can I learn easy ways to use Numbers?

It's best to learn by doing, and if you have questions there are plenty of experienced helpers willing to assist in the Numbers for Mac Community.

Here is its User Guide: Numbers User Guide for Mac - Apple Support

MS Excel and Numbers do the same thing. They just do it differently.

Apple stores offer some courses; however because of the nature of Numbers, and your familiarity with Excel, you should be able to make the transition from Excel to Numbers quite easily with practice using "dummy" files to experiment and play with.