Overweight guy fancies trying a triathlon :-)

Hi
I'm an overweight guy. Unfortunately lockdown added on the pounds.......but I want a challenge (apart from getting into better shape).
So I have decided to try a triathlon. I have no idea if I will have the determination needed to get to that level but I am going to try.

I am giving myself over a year to train. I believe the local triathlon to me this year is in July, so would try and do that next year (if that makes sense)

Being overweight I am concerned about if my joints will handle the run training (at the moment and even before I added all this weight, I could not run very well).

In the past I was an "OK swimmer"
In the past I was an "OK cyclist"

I have so many questions but thought I'd introduce myself instead.

Hi