Which Bike Trainer and bike combo

I want to do some biking. I live in Bangkok where traffic is deadly! There is a cycle track at the airport and I plan to go there weekends, but have to get a 40 min taxi there and back so can't go every day.

I want to get a bike trainer, which one should I get? I would like it to be a smart trainer and would like to try zwift. Should I get the Kickr core? It's available here in Bangkok but need some guidance on if I should get that one or another? Price wise, that's about as high as I can go.

I am a total beginner, I need to get into some exercise to try and get fit. There are a few series of triathlons here and some for beginners like sprints - 400 m swim, 20 km bike and 5 m run.

I want to train for these as a challenge. I can run outside (traffic, noise and pollution are terrible but doable) or get the train to a park. I can swim in a pool but need a trainer set up at home to cycle.

Can you please advise on which trainer plus bike to get? The bike I was thinking about a cheap option from decathlon - something like this: https://www.decathlon.co.th/en/p/8389937_-triban-100-grey.html#/5880...

Thanks for the help!