Have you planned a walk that is a bit expensive then a day tripper ticket might be what you need.
if the walk is within the old strathclyde area
Remember the full cost from your frontdoor and back to your door and remember to factor that in if you can team up with someone that stays close to you get a 2 person card.
The Daytripper ticket gives you unlimited travel for one day by rail, Subway, most buses*, and some ferries in the Strathclyde region. Tickets are valid after 9.00am on Monday to Friday and all day at the weekends and on Glasgow public holidays.
Current price is
Price: £20.30 for two adults and up to four children or £11.50 for one adult and up to two children from any staffed rail station.
See if you walking area is covered.