The Gospel today is the Passion according to St Luke (22:39-71; 23:1-53). You can find the Matins readings (from Jeremiah) here.
There are specific antiphons for the psalms for the day (MD 263*ff) for Lauds to None, as well as the proper texts for passiontide. The canticle antiphons and collects for the day can be found in the Monastic Diurnal at 264*ff.
Tenebrae of Maundy Thursday
Technically, under the 1962 rubrics Matins and Lauds of Maundy Thursday (viz Tenebrae) are not allowed to be anticipated.
However, this is one of the most widely ignored of the 1962 rule changes, ignored for entirely practical reasons.
If you happen to be able to attend Tenebrae, do make sure you have said Vespers and Compline of Wednesday first.