I've only built three kits. Here are a few thoughts.

If your kit has not arrived, get a head start by downloading the manual from
http://www.greatplanes.com/parts/index.html#kits

In addition to the manual for your Extra, download the one for the PT-40. If any steps or descriptions in the Extra manual are unclear, find something similar in the trainer manual and it will probably have a better description.

The pictures in the manuals do not always show pins or clamps but the text refers to them where they are needed.

I looked at the Extra manual and it looks like it could be built with wood glue or CA pretty easily.

If you use thin CA you get the parts positioned and pinned as perfectly as you can and then apply the glue. There is no time to adjust anything.

Medium CA is applied before the parts are joined but you do have to be fairly fast.

Wood glue is applied before the parts are joined and you have a few minutes to get things lined up.

I use thin CA, wood glue, and 30 minute epoxy.

The Extra calls for epoxy in several places. They mention 6 minute and 30 minute. I can't use 6 minute. It sets so fast I can't use it so all epoxying I do is with 30 minute.