Anyone know where i can download lightroom 5.0?

your license is good for the last lr 5 update (5.7.1) so you may as well start with that.

Downloadable installation files available:

• Suites and Programs:  CC 2014 | CC | CS6 | CS5.5 | CS5 | CS4, CS4 Web Standard | CS3
• Acrobat:  DC | XI, X | 9,8 | 9 standard
• Premiere Elements:  13 |12 | 11, 10 | 9, 8, 7
• Photoshop Elements:  13, 12, 11, 10| 9,8,7
• Lightroom:  6|5.7.1| 5 | 4 | 3 | 2.7(win),2.7(mac)
• Captivate:  8 | 7 | 6 | 5
• Contribute:  CS5 | CS4, CS3

Download and installation help for Adobe links

Download and installation help for Prodesigntools links are listed on most linked pages.  They are critical; especially steps 1, 2 and 3.  If you click a link that does not have those steps listed, open a second window using the Lightroom 3 link to see those 'Important Instructions'.window using the Lightroom 3 link to see those 'Important Instructions'.