Membership expiry is best handled in the shopping area, via 2 templates set to contact on the 1 month and 14 day prior.
Note, If you use the email campaign, there are some issues you have to consider.
You could create a single step email campaign, and automatically add members who are due for expiry.
However, once added to the email campaign, there is no check on the members to see if they have already renewed their membership.
In the second year of membership, the member has already received the first step newsletter, and so will not get further notifications.
Consider using the templates specifically for "membership expiry" in the "product automation" tab of each product..
Another option is to run with 1 campaign for the first year, then terminate that campaign, then start a new campaign, and so on every year.