You don't need to go to uni with a strategy! Be open to making friends with anyone, whether on your course or not. In later years you will naturally tend to spend more time with medics as other courses are shorter so your other friends may well have left, but early on I think it's good to have a mixture of friends. Medics at some unis have a reputation for being cliquey and arrogant, which probably isn't true, but if you make friends with non-medics you can help challenge that stereotype.
My closest friends are a mixture of medics and non-medics, though admittedly they are two mostly distinct groups. Both are useful to have around.