Would anyone attempt

I found this plant.

Would it make for a good bonsai? Should I trim and turn it Into a bonsai or is it too old?

Thanks

sure why not? give it a shot!

I do not know your horticultural knowledge but i would keep it alive for a year or so. Meanwhile, fertillise it, make it vigorous, and look at it a thousand time to see what you want to do with it.
Each tree species has its own care guidelines and moments in the year when to do what. First figure out which species it is ( if you don't know) and work from there.
Bonsai is a marathon , not a sprint, so no need to rush things

too old is certainly not the case. Age is one of the things that helps make a tree look realistic.

Besides that, the previous poster has made all the right comments, no need to repeat from my side.

Thanks you for your comments.

I’ll give it a crack.

How would you get it growing vigorously again?

It’s some sort of pine.
I’m guessing it’s been in the same pot for a long time. Should I give the roots a trim and replace the soil?

Is the substrate draining good?

Nope, not pine. Juniper.

Yes

Its a juniper.

Ive never tried a bonsai with this specie but I had a couple at my parents place I would take care of and trim them proprely.

After major cutting I always apply live oil on the trunk...
It will act as a repelant against insects and keep the trunk looking a nice dark red.