think you will struggle to find somewhere walkable - may need a car or be prepared to bus ]
Oak Farm at Bagington is ok - certainly cycling distance from uni. Natan also ok - have known a few people happy there.
Castle Hill in Brandon offers DIY and grass livery in large herd - great if you have a sociable gelding - good school etc but is a riding school and not everyone prefers that. Full Livery also good but more expensive
There is a DIY grass livery on Crackley Lane next to Crackley Woods Kenilworth which is also close. Also the Weetmans Farm in Kenilworth.
If you have a car, Million Dollar on here runs a livery south of warwick with a good reputation - Bromson Hall near Ashorne which seems to have good reputation. Also Finwood Barns - bit further out but looked lovely last time I was seeking livery there.
Pm me if you prefer - I know a lot of the neighbouring liveries by repute !!
The only one I can think of is Hurst Farm. They don't have an arena or anything like that though. Very good off road hacking right on the door step, and quiet lanes to hack round too, though no street lights. In the summer months, the local amateur riding club host a show there every other Sunday, show jumping from teeny tiny up to 2ft9 and mounted games.