And yes, I have the tools, however I think my multimeter is broken.

 

And when I put these sections in parallel it won't change anything in these calculations, right?

If you have a series string with 3 LEDS and a resistor that has 100mA, and than add in parallel a second identical string with 3 LEDS and resistor, you will now have 200mA flowing from the battery.
But the individual string calcs are the same.
have fun

 

And yes, I have the tools, however I think my multimeter is broken.

These are very good value for money!
https://www.ebay.com.au/itm/AU-AN80...279279&hash=item3fa7e0d3ef:g:bXwAAOSwdzlbbWKP
You can get a lot cheaper ones too. A multimeter is necessary. Go get one!

 

Thank you so much for taking time for this project. I think it's going to be great
And yes, I will go get one. I think I have one I can "borrow" from someone...

 

That's ok.
Please let us know how it all works out .

 

I definitely will