google maps api help

hi all, a very simple project needing some help to get what i need - someone with google maps api knowledge will be able to sort this in an hour. i have already set up a maps page that reads its data from a google sheets. Im using the Google Maps Javascript API - Id like the map to; 1) cluster the markers on the map 2) use a different icon other than default (i can change later through the code) 2) filter the markers based on date/time column in my google sheets (slider) 3) filter the marker based on another column in my google sheets. Most of the code already established but my lack of knowledge is frustrating me! Could someone help tonight please... Needs completing tonight i have $25 available. Thanks