WANTED: 1mm coral sand

Hi All, Hope this is OK to ask but I am after some tips for a new set up, I have bought a pre-owned Juwel Vision 180 its bare and cleaned, it came with a Fluval 207 external filter. I will be buying some carbon and bio-ceramic for the filter so that side of things will be ready. I wasn't sure on substrate but like the idea of sand, I was torn between white or black and ive read multiple posts about black sand being a little bit easier on the eye in terms of waste etc on the floor. I have an air pump but what type of air device should I get any suggestions? should I just aim for a long air bar? also can someone explain how I cycle my tank and for how long for? i hopefully want some clean up crew and with my limited knowledge i believe that would be either a plec or shrimp or snails is this correct, any tips on this? Also should I invest in a water test kit and if so, any reccomendations? any help is very much appreciated.

Setting up a small 50 L tank for my grandchildren and was look for some gavel and a filter if anyone nearish to Crawley has anything?

Just getting back into the hobby and just wondering what shops people reccomend, im after some black sand to start with. thank you in advance

Has anyone got any gravel for sale?