Overwhelmed

Hi folks. After many years of working at home since covid I have now got a job with a commute again. 6.5 miles away most of it down a nature trail (mostly paved) by the river and under trees. So very lucky.

Now where I've become overwhelmed is knowing what to buy for this commute. There's so many bikes and so many budgets.

My budget as I'm just starting a new job is on the lower end of the scale.

I keep seeing about decathlon riverside 500 currently on sale at £300. Would this bike suit the usage case of around 6.5 mile each way probably 5 days a week.

Also looked on market place I've seen this specialized sirrus x 2.0 but do you think second hand is risky?

Any advise or recommendations to settle the overwhelm and nerves of making the wrong call will be appreciated