I am brand new here and with air guns, need some direction. I bought a new FX Crown MKII in a .25 cal, I have a new Hawke Sidewinder 30 FFP scope, I need rings, ammo, best way to charge my gun, and anything else you could recommend, where is the best place to get this stuff ? I will be using the gun just to plink around, shoot small varmints, maybe a little target shooting, right now not looking into long range ( more than 100 yards ) , any help would be greatly appreciated, thank you.
You really dove into the deep end, huh?
No worries, by starting out with such a high-end rifle, you've probably saved yourself money by avoiding cheap and in many cases unusable/mediocre equipment, like I, and many others fell prey to early on in our air gunning journey.
As to charging your FX Crown, I recommend you purchase a carbon fiber, SCBA tank with the pressure gauges, such as the kit pictured in the link that follows:
https://www.topgun-airguns.com/product/tiger-shark-410-cu-in-74-cu-ft-4500-psi-tank-copy/ That tank is listed as 74 cu ft., which is a nice sized tank. However, that same vendor offers a larger model, listed at 97 cu ft, I believe. You may be able to research and find the SCBA tank and gauges cheaper than the one I linked to.
You can get this tank filled at a scuba dive shop, possibly a paintball business and even a fire station (I'm told, although I've had no such luck with the fire stations). You will want to use clean, dry air in your air rifle. I notice that the vendor in the link will fill your tank prior to shipping it to you, if you select that option. This may slow the shipping process.
At some point you may decide to invest in a high pressure air compressor -- these can cost anywhere from a few hundred dollars to several thousand dollars. My understanding from reading the airgun forums, is that Alkin and Bauer are the best compressors on the market. I happen to use a Nardi Atlantic 100. I purchased this compressor more than 5 years ago and have not had any failures with it to-date.
https://www.pyramydair.com/product/nardi-usa-atlantic-p-air-compressor-electric-4500-psi-300-bar?a=5218 As for as scope rings, you have check the size of your scope tube and proceed from there. I have numerous scopes, the majority of which have 30mm tubes. I also have a 34mm tube scope and a one inch tube scope. Make sure to get the correct size. I suggest purchasing quality scope rings to mount your scope.
I realize this post is rather lengthy, but there is much to digest early-on to avoid common costly pitfalls that could damage your valuable equipment and possibly cause physical injury to you and/or family members.
So, take your time, research and be careful when dealing with HPA.
Good luck.