Getting to/from the ground
The ground is a 25-30 minute walk from the station and town centre. You can catch a bus from the bus station, which is just over the road from the train station. The number 1, which goes right past the ground, runs every 15 minutes. But if you leave it late to head for the ground the bus will get stuck in match traffic, as would a cab. It's worth checking to see if your train back after the game stops at Mill Hill before Blackburn. If it does, heading there rather than Blackburn. Not only is it much closer (a 15 minute walk), but you'll be able to get a seat, which'll be pretty much impossible for anyone getting on at Blackburn. Plus there's a decent pub (the Navigation) handy for Mill Hill, and there's a Spar and a couple of off licences between the pub and the station. Mill Hill is the same price as Blackburn.
If you're driving down then don't even think about the car parks around the ground unless you're happy to be stuck for an hour or so after the game. You should be able to park in the streets off Bolton Road or Branch Road if you get there reasonably early, otherwise there are some industrials unit on Branch Road that offer parking for a price.

The nearest pub to the away and, the Fernhurst, is designated as an away fans pub. However, it'll obviously get full very quickly. An alternative if you're down in the car is the Golden Cup. It's a lovely little pub with a village feel to it and used to be a fine place to go for a pre-match pint. That though was before they built the motorway right past it. Nowadays it's the first pub people see when they come off the motorway, hence it gets VERY busy. I'd suggest getting in a double, or even triple, round at some point unless you want to spend a good chunk of your life waiting to get served. It'll take you 15 minutes to walk from here to the ground. An alternative to the Golden Cup is Uncle Jack's, which is slightly closer to the ground. It used to be home fans only, but not nowadays apparently. A final suggestion for anyone driving over is Livesy Branch Road, possibly parking in the streets to the north of the ground. Even if you park up by the Golden Cup the extra time spent walking to/from the pub will probably be more than made up for by reduced time waiting to get served. There's a stack of pubs along this road, and presumably those furthest from the ground will be less busy.
Most people exiting the station normally head straight for the nearby Adelphi. However, even though it was refurbished not long back, it may well be closed, not for the first time. There's very little choice in the centre. An obvious place is the Postal Order, which is a Wetherspoons outlet. This will no doubt get very busy. It may be worth keeping going another 200 yards and trying the Sun Hotel. Better than both though is the Drummers Arms, a micro pub which opened in 2016. They have five cask beers, all competitively priced, and the place gets universally good reviews. Otherwise hop on a bus or jump in a cab and head for Livesy Road (see above).

Pub map
Football ground guide