I have a late 2011 MacBook Pro ( mbp )

Tparh96 wrote:

I have a late 2011 MacBook Pro : my question is , what can I do in the way of upgrades in order to have it running OS Catalina ? it currently has 8 GB Ram and a 500 GB HDD / I plan to install a 2 TB SSD ,as well as 16 GB Ram ........

Not possible.

Your hardware will not even support Mojave....

You are limited to High Sierra as the last macOS it will support:

macOS 10.14 Mojave - Technical Specifications:

macOS Mojave - Technical Specifications

Upgrade to macOS Mojave - Official Apple Support

macOS - Official Apple Support

https://itunes.apple.com/us/app/macos-mojave/id1398502828?mt=12

MacBook (Early 2015 or newer)

MacBook Air (Mid 2012 or newer)

MacBook Pro (Mid 2012 or newer)

Mac mini (Late 2012 or newer)

iMac (Late 2012 or newer)

iMac Pro (2017)

Mac Pro (Late 2013; Mid 2010 and Mid 2012 models with recommended Metal-capable graphics cards)

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Identify your MacBook Pro model

Identify your MacBook Pro model - Apple Support

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macOS 10.13 High Sierra - Technical Specifications:

macOS High Sierra - Technical Specifications

https://itunes.apple.com/us/app/macos-high-sierra/id1246284741?ls=1&mt=12

How to upgrade to macOS High Sierra

How to get old versions of macOS - Apple Support

MacBook (Late 2009 or newer)

MacBook Pro (Mid 2010 or newer)

MacBook Air (Late 2010 or newer)

Mac mini (Mid 2010 or newer)

iMac (Late 2009 or newer)

Mac Pro (Mid 2010 or newer)

It's 11 years old and Apple considers it obsolete. It's not supported. How much time, money and effort do you really want to expend on an old obsolete Mac? Even if you can make the upgrades, the rest of the Mac is old and tired and generally considered to be near or at its useful life.

High Sierra is the latest OS you can install.