Brand new

Welcome Nikki!  

It's great that you're starting a 45-year journey to be that woman in her 70's doing triathlons.  

With your track & field background, you should already understand that consistent and quality workouts are important.  It's a lifestyle.  

Newcomer advice:

Swimming is very technical.  You may marvel at that "out-of-shape" swimmer who swims circles around you.  Understand that (s)he probably spent years swimming competitively as a child and learned good technique and that "feel" for the water.  Instead of thrashing around by yourself, get some instruction and learn the good technique.  

What you need in a bicycle is 2 good wheels, brakes, and a comfortable riding position.   Think about the types of riding you'll do from high-speed training rides to cruising the neighborhood to bombing down singletracks and start with a versatile bike even if it isn't the "fastest" in any one thing.  I had a 10-speed (skinny tires, dropped handlebars) in high-school that I rode for years, but cruising the neighborhoods with my family, I was forever dealing with glass and flat tires.  I bought a mountain bike and started enjoying the rides more.  Now I'm back to road/tri bikes mostly but still ride the mountain bike around town for errands.  In addition to a bicycle, you'll want a helmet, repair kit, frame pump or inflator, and sunglasses (to keep bugs out of your eyes).  What's the best bike to own?  THE ONE YOU RIDE REGULARLY!!

You've already got a running background.  This is where the next bit of advice becomes important.

Forget your past capability!  It doesn't matter if you *used* to run 5 minute miles.  It doesn't matter if you *used* to run 6 days a week.  You'll hurt yourself trying to get back there quickly and frustrate yourself trying to get back there period.  You won't recover as quickly at 26 as you did at 20.  You won't recover at 50 as quickly as you did at 26!  I'm trying to keep this in mind as I fall off the triathlete recovery wagon (i.e. I start training again).  

Psyche may be your biggest battle!  

Our minds are wonderful creations, capable of a range of thoughts and somehow our experiences often align with our mental predictions.  

If you approach learning to swim like a battle, it will be one and you'll most likely be frustrated with every little defeat.  

Channel your inner sea-turtle or dolphin or even sea otter.  Set a mental image of that serene, graceful, tropical lagoon and you moving effortlessly through the calming waters and you'll find delight with every new discovery.