Welcome to FT andypendi64!

BA113 is operated (usually) by a 747-400, which will have a slightly dated version of BA's economy class, but which is, in many ways, superior to a lot of the offerings on this route. The aircraft itself is probably 15-20 years old at this point. You'll be fed and alcohol is complimentary (included in the price of your ticket). Don't get too excited about the inflight entertainment, as this is very dated and in no way comparable to Emirates, for example, but no worse than AA or UA.

2h20m is plenty of time to connect in Heathrow, it's a relatively straightforward process. Basically just follow signs for flight connections. Actually, it's probably too much time, but you can never be sure.