new to the forum, my bike......

[Esoteric1]

A lot bikes do this, you need to be in first gear as you approach a junction. So gearing down as you slow down. What I do which helps a smooth gear change is I give the engine a gentle rev with the clutch fully in immediately before gearing down. 1st can be hard to find when you are tapping down all the gears from a stand still. The other clunking when setting of for a while is likely to be the chain needing adjusting. A rattling chain sounds like there can be something wrong with the engine.

They are easy to tighten, just make sure the gauges are equal both sides and that there is still a little slack in the chain (About 1 inch of lateral movement upon forcing the chain up with your finger)