my mac book is late 2008 and i need help to update the software

Depending on a few important detail factors, the system software may be

upgraded. ~ Perhaps you could state here, the present system installed?

Most specs for both different similar name MacBooks are as follows:

More than one build model 'late' 2008 MacBook identifies as such. Last

better one, with Aluminum unibody, and two choices of CPU. The First,

was white polycarbonate plastic; with hardware limitations, on upgrade.

(Much lower specs with 'white poly' macbook, than last aluminum body unit.

Made the second a far better model; which later morphed into MacBook/Pro.)

Since you have the macbook right there, you should be able to tell more!

(online resources & specs are from reputable sources + freely accessible)

• [White 'polycarbonate']

MacBook (13-inch, Late 2008) ~ first, earlier 'late '08' build:

Introduced October 2008

Discontinued January 2009

Model Identifier MacBook4,1

Model Number A1181

EMC 2242

Order Number MB402LL/B

Original OS Mac OS X 10.5.4 (9E27, 9E29) ~ or retail DVD for Snow Leopard 10.6(.8)

Maximum OS Mac OS X 10.7.5

Hard Drive Interface 1.5 Gbps Serial ATA (SATA)

Optical Drive Interface Ultra ATA/100 (running at UATA/66)

Maximum Memory 6.0 GB (Actual) / 4.0 GB (Apple)

Memory Slots 2 - 200-pin PC2-5300 (667MHz) DDR2 SO-DIMM

Graphics Card Intel Graphics Media Accelerator (GMA) X3100

(this build model hasn't the hardware to upgrade past Lion 10.7.5)

• [later second 'late 2008' version]

"MacBook (13-inch, Aluminum, Late 2008)"

Introduced October 2008

Discontinued June 2009

Model Identifier MacBook5,1

Model Number A1278

EMC 2254

Order Number MB466LL/A (2.0 GHz), -or- MB467LL/A (2.4 GHz)

Original OS Mac OS X 10.5.5 (9F2088, 9F2114, 9F2533)

Later OS Mac OS X 10.5.6 (9G2133) (or- retail DVD: Snow Leopard 10.6(.8)

Maximum OS OS X 10.11.6 (15G31)

Hardware Test AHT 3A147

Hard Drive Interface 3.0 Gbps Serial ATA (SATA)

Optical Drive Interface 3.0 Gbps Serial ATA (SATA)

Maximum Memory 8.0 GB (Actual) / 4.0 GB (Apple)

Memory Slots 2 - 204-pin PC3-8500 (1066 MHz) DDR3 SO-DIMM

Graphics Card NVIDIA GeForce 9400M

(specs courtesy of mactracker database application)

..other resources are online; each, differ somewhat..

To upgrade early (white/poly) late 2008 macbook to last OS, requires

either Snow Leopard, fully updated; then go to Mac App Store to

order Lion 10.7.5 - for $19?.

-OR- to upgrade "Aluminum Late 2008" and if not already, update/upgrade

to last Snow Leopard, go to this page link to study and get 'download' for last

supported Mac OS X 10.11.6 "installer" from Apple Servers. ~ Read carefully:

• How to upgrade to OS X El Capitan - Apple Support

https://support.apple.com/en-us/HT206886

Depending on what you actually have ~ the devil is in the details.

Then to see IF what you have, is ready to get later supported OS.

Good luck & happy computing!🌞🎣