Back in the pool

Doing lengths after a break of approximately 17 years. The local pool was surprisingly busy. There were lanes for people who looked serious and intense, one lane with a few people swimming quite slowly while looking grumpy and one lane with two people swimming pretty quickly whilst looking like they'd managed to trap an intimate part of their anatomy painfully amongst the gussetry of their high performance swimwear. I decided to steer clear of the lane swimming to start with, as I had no understanding of the protocols and unwritten rules that were seemingly hardwired into all the other pool users at birth. So instead I did battle with the middle-aged-overweight-doing-something-to-tone-up-supposedly-but-in-reality-just-looking-for-a-guilt-free-way-to-badmouth-my-consistently-disappointing-husband-to-my-equally-chunky-chums-under-the-guise-of-exercise-women. Which was nice. The trouble with the larger lady in the pool environment is their propensity to occupy a sizeable area of real estate, and a large collection of large ladies well you get the picture. Anyway this is serious swim training for a serious attempt at a serious triathlon so breast stroke it is right? The distance required is 16 (although maybe 17?) lengths of the pool. My first attempt including a couple of evasive manoeuvres the odd slow length tailgating and a scary moment when I was forced to stop by a group of menopausals comparing bingo wings was 8 minutes. I then went into the lanes for a go at front crawl, I managed four lengths in 1 min 40 before the intensity of the situation was too much for me and I fled to the free swim area. I think with a bit of work I should be able to get the swim down to low-ish 6 minutes.
So for two of the events I've got a rough baseline and I've also developed targets:
Swim 400m* - Current 8min - Target 6min 20
Run 5k** - Current 24min(ish) - Target sub 21min

*It might be 420m in the actual event but hey-ho
**I think the Tri distance is 7k, so I need to work those times up a bit once I've devised a suitable 7k route

Now this just leaves the bike. Now I've never ridden a road bike, ever. I don't even own a bike of any kind. So if any kindly soul has a spare/broken/unwanted road bike (or part thereof) that they are desperate to get cleared out of the garage/shed/hallway then (assuming it would be of an appropriate size for a stump, something 48-50cm I guess from my know nothing perspective??) I'll help you find it a home with pleasure.