That's quite a lot for a 7x4?, and you're first layout don't make the mistakes I made trying to cram as much in trackside as possible?, golden rules are:
1 keep it simple,ie maybe a branch line single track with a nice terminus on one straight side? With bay platform, small goods yard,
2 if you use peco unifrog points no need for wiring the frog points are already dcc friendly!!, believe me you don't want the headache of over complicated wiring??, keep this simple too?
3 try and make the railway look like it was laid in the landscape ,not the land around it?
4 make sure you wire every piece of track to the dcc bus under you're layout that way no problems with trains stalling ?,
4 and finally buy a nice simple dcc controller set which hasn't got complicated function systems for getting the blumin locos to do anything!!?, lenz l101 is a good entry level set nice and simple to use and made by the Germans!!, so their instruction manual is easy to follow?, after all they invented the hand book!!,
5 and finally don't rush it ?, glue your track down not pin it?, and happy modelling!!?