Can "this" refer to two items?
"This" refers to "wealth".
... you are instantly confronted with a wealth (of information and semiotic signals) to guide your decision-making. This will be everything from recognisable brand names...
If you remove the word "wealth", you'll get:
"...you are instantly confronted with information and semiotic signals to guide your decision-making. These will be everything from recognisable brand names"