The first thing you need to do is to install XLE on a computer that you can use. XLE is currently available under an open source license and you need to obtain license first before you can install XLE.
You can find up to date information about XLE and the ParGram effort on the ParGram/XLE Redmine site.
The general XLE page provides information about XLE and tells you how to obtain a license for XLE.
The XLE Documentation provides information as to how to install XLE.
Try out some of the LFG grammars on the INESS Bergen XLE site. Try at least 5 sentences with at least one of the grammars and note down peculiar things you notice or particular things you have questions about.
The following provides links to relevant reading material or sites mentioned in Lesson 1 where those are available.