Dechlorinator and filter setup order

I'm not even sure if anyone will be able to answer this in time but I haven't been able to find a good answer anywhere else so I thought I'd give this a shot. I've got a new tank coming in the mail tomorrow and then a filter coming the next day. By tomorrow I'll have everything I need to set up the tank besides the filter. So my question is, is it alright to set up the tank and start the dechlorination process and then install the filter when it comes, or do they need to be done at pretty much the same time when setting up a tank? This is my first time setting up a betta tank so I want to make sure I do everything in the right order. Thanks in advance for any help or advice!