>>I need to find some sort of exercise hobby, or a hobby that requires physical movement. <<

You might try getting a big list of hobbies, pick the ones that sound promising to you, and then date them for a week or a month to see which you like the most. No big commitment to any one yet, just trying new things.

>>Knitting, Weaving, Crochet, Cross stitch. I aspire to learn to water color (someday) and get back into sketching (someday).<<

Crafts are fun.

>>More projects around our house & land (we live on five acres).<<

I have 2 acres here. I know that feel.

>> Forever planning upgrades to those. This year we'd like to get a playground built for our kids.<<

Nature playground, storebought, or what? With kids that little, a patio, sandbox, or play garden is likely a good place to start. Put out a nature table or box for collecting loose parts. If you're crafty, tree cookies or tree blocks are great things to make. You can find or make a ton of natural toys free or cheap.

Think modular and expandable. As the kids grow, you can lay an adventure trail through your large yard by adding a balance log here, a tree swing there, etc.