Apple Watch advice please!

[SantaMonicaPier]

Planning to get my first Apple Watch so will go for a cheaper model, prob SE. I want it for fitness tracking more than anything but also to easily see messages etc rather than having to get my phone out. I would ideally like it for music when running but does that mean I'd need a cellular version with a separate SIM contract if I didn't take my phone with me? Any tips much appreciated as my ideal is not to spend much more than £250. Thanks in advance

[MissConductUS]

I think Spotify will let you download music to the watch.