there are about 40 links after i login in as a test user. do i have to make a separate test case for all 40 links? how do i go about it?

also, to check all these links, i need to login first. do i, in every test case, show that i have to login? i mean to say that, the first 3 steps for every test case will be just me logging in. is that a good approach to writing test cases?