Advice on new bike

I just bought a 1997 Specialized Stumpjumper....I believe that is the year although it may a 1996 and not sure of anything else.
i bought it from a co-worker that only rode it few times and hasn't rode it for 6 years. I only paid $25 for it and it is great shape. It is being tuned up and it has road tires on it. This is the first bike that I will ride in 20 years!!

Is that a fair price? Did not want to cheat her but it was her asking price?

Is this okay to train with until I can afford a road bike?

Does anyone much about the bike? I have been searching info on it but can't find a bike that looks like it....it is black with yellow writing and yellow front shocks.