We are currently using Trac without Agilo for Scrum, because we haven't found it before the project started und did not yet switch to it.
So I have a few tips for running Trac in a Scrum project without it:
1. Customize your ticket types
Go into your trac admin and configure a new ticket type for product backlog items (like ... "requirement", or just "product backlog")
This is importent, because later on you can create reports based on the ticket type.
2. Customize your tickets
You should add two new properties to your tickets: "Story points" and "Remaining time."
Open your trac.ini file (located in the conf directory of your Trac instance) and add a new (?) area in the file:
[ticket-custom]
remaining_time = text
remaining_time.label = Remaining time
story_points = select
story_points.label = Story points
story_points.options = |0|1|2|3|5|8|13
story_points.value = 0
3. Create customized reports
You will need some custom reports, like a report showing all the product backlog items, etc.