Well, I would say it could be OK, if you approach with care.
If it was me, in your situation, I would be taking someone that is experienced with such vehicles along to give it a once over.
And listen to what they have said^^^^^^. Disco 1s are one of the rustiest vehicles ever made.
And it is highly likely that you will spend more on repairs and maintenance in the first year as you spend on the vehicle.
The cambelt is important, if it breaks, it can cause expensive damage. So you need to know when it was changed, or get it changed straight away.
Also, as a novice, why do you think a lift kit and mods are needed? A standard Disco is an excellent off roader, cheaper to insure, and easier to maintain and order parts for.
If it was me, I would be looking for a clean standard vehicle, that had been owned by an old couple, and used for towing their caravan once a year.