1. Anyone recommend a good smart speaker.
2. Do I bluetooth music from Spotify to the speaker.
3. Anything I need to watch out for ?
1) Yes, I can recommend a good smart speaker.
2) No - if you want a smart speaker bluetooth is not needed. Bluetooth will work with a dumb speaker that has bluetooth functionality.
3) Some smart speakers are a bit trickier to set up than others.
The cheapest and most ubiquitous smart speaker is the Alexa Echo. The Dot is very reasonable and actually delivers a fair amount of punch for its size, although you won't be running a disco in a large lounge with it. Alexa can integrate with Spotify although there is a little bit of setup to do so that you can say "Alexa - Play the best of Phil Collins" rather than "Alexa - Play the best of Phil Collins on Spotify".
The rival to Alexa is of course the Google Nest, although the experience will be broadly similar.
The premium audiophile option is Sonos with built in Alexa (although note that Alexa does not have full functionality inside a Sonos) - although at times the actual Sonos interface can be annoying if you have Alexa set up you don't have to use it.
Other brands are also available with Alexa or Google built in.
One of the advantages (or not) of Alexa is that if for example the rest of your family have Alexa's you can create an Alexa group which will allow you to use them as a rudimentary intercom - the disadvantage is that your grandchildren can have fun by asking their Alexa to play spooky music on Granddad's Alexa.
Sonos, Echo etc can all be grouped so that you can gradually add more speakers throughout your house should you want to do that. Sometimes it's quite nice to have a speaker in the lounge and kitchen so that you can listen to music as you move through the house.
The key question is how loud do you need the music and how much do you want to spend?
As for Podcasts they are basically an informal radio 4 programme usually. Just people chatting about whatever the podcast subject is. I listen to a lot of comedy podcasts. BBC broadcast some things as podcasts e.g. the Infinite Monkey Cage.