[Closed] Exercise flexibility

For many years my exercise has comprised of cycling and walking.
Now I am on a bit of a health kick and have bought a kettlebell to do high intensity interval training workouts from youtube.

I have enjoyed the exercises and the fact that I do not have to trek to a gym and so can have everything done in less than an hour.

Some of the exercises such as squats have made me realise how inflexible I have become and I am struggling to have good "form" and get low enough.

Things do seem to be improving gradually but I am wondering whether it would be beneficial to do some stretching (yoga?) to supplement the kettlebell stuff. I do not really know where to start with this and so am looking for some suggestions. Ideally I would like something I could do at home rather than going to a class but I guess I could do that to get started.