Welcome and well done to your 1st post. For all those times I've visited Prague, not once did I use the tram, the Metro yes, stopping in Starometska city centre.
Prague is way better seen on foot, unless of course you're going further out of the city centre.
A well-recommended one day tour out of Prague is a visit to Karlovy Vary, a spa-town where it includes a roof-top swimming in one of the hotels and a visit to a beer-town, i forgot the name. Karlovy Vary is awesome, a couple of my friends who were on honeymoon in Prague loved it and so were my other friends who went there.