I assume you’re not asking a question? If you are it isn’t clear

I didn't see any lockers whilst I was there but that isn't to say there aren't, they may have just not been visible.

You can. Just get a jacket or something with you it’s a bit cold

Rotterdam Centraal is really very easy :) The trains to Utrecht mostly go from platform 14 / 15, around that number!

Dear Atef, Most probably you'll have to change in Rotterdam. However it's very easy and usually takes 2 to 5 mins maximum. Once you land in the station look at the acreens to know which platform is yours and head directly to it. You can also check the Dutch trains' website.

Hola La estación de autobuses se encuentra en la calle Conradstraat que está a 6 minutos a pie de la Central Station.Saludos

I am not sure but I don't think so. Leaving luggage in such a busy place isn't very common in these times of terrorist attacks

Yes, there are lockers. Go to ns.nl and klick on the icon for English top right. You'll get all the information you'll need. There are plenty cafés and such. Dudok would be best but there's a Starbucks too.

Según llegas en el hall principal hay unas maquinas amarillas donde podrás comprar tu billete para todas las ciudades importantes de Amsterdam. Pasan con mucha frecuencia y si estás atento dependiendo del tren que cojas puedes ahorrarte bastante tiempo debido a las paradas intermedias que tenga. En la maquina solo debes seleccionar el destino. Hay dos tipos de máquinas amarillas, las que te dan el billete y otras donde puedes recargar una tarjeta de transporte que usan los holandeses. Yo te recomiendo que saques los billetes normales. En esta estación también tienen a unas ventanillas donde en diferentes idiomas te podrán atender un empleado para resolverte las dudas. Espero haberte ayudado.