Ive read the sheldon brown articles but i still have questions. I'm converting an old 10speed road bike so a single speed (freewheel). Can i use the same back wheel and just remove the freewheels and replace with spacers/a new freewheel and whats the best way to go about getting the inside sprocket off if i have a 1 piece crank system? thank you.

if you have a wheel with A free-wheel cassette, you can use the cassette, redish the wheel and use a single speed cassette,

If its a cassette hub, you can set a cog and some spacers

how can i tell the difference? and how can i remove the freewheels?

If you have a 1pc crankset, I'd go dollars to donuts that you have a freewheel instead of a freehub. What you'll need to do is remove the entire cassette and thread on a BMX freewheel.

where can i get the tool to remove the freewheel online? it seems to be two prong.

the park FR-2 is a two prong freewheel tool:
https://www.parktool.com/products/det...=4&item=FR%2D2

these can be found in LOTS of local bike shops (LBS), or do a google search for online outlets

...

like me, with the complete set of park removers that have been used once each, and now sit in the toolbox laughing at me,........

he's right, just take it to the LBS and have them do it for you