I was also very new to this just a few weeks ago and have the same machine as you. I have bought a fair number of bits but find myself using only 2 or 3 so far regularly. I would say these are not cheap bits though but like a lot of tools you get what you pay for and I already wore down a couple of the cheaper ones and end up spending more on throwing materials away…

A good V bit: Amana Tool 45624-K SC Spektra Extreme Tool Life Coated V-Groove 60 Deg x 1/4 D x 31/64 CH x 1/4 Inch SHK 3-Flute Router Bit https://www.amazon.com/dp/B07JDFKDMC/ref=cm_sw_r_cp_api_glt_fabc_Y0TFGZH34DKC3B8MSJNR?_encoding=UTF8&psc=1

A good endmill: Freud 1/16" (Dia.) Double Flute Straight Bit with 1/4" Shank (04-096),Red https://www.amazon.com/dp/B00004T7B2/ref=cm_sw_r_cp_api_glt_fabc_0YTR7JA649RFETM8HNDQ?_encoding=UTF8&psc=1

I also purchased the 1/8” version of the Freud end mill but use the 1/16” more. Also notice these are 1/4” bits so as you mention you will need a new collet.

I would also recommend this book. You can learn much of this on your own but it will save you quite a lot of time. The Newbie's Guide to CNC Routing: Getting started with CNC machining for woodworking and other crafts https://www.amazon.com/dp/1726471020/ref=cm_sw_r_cp_api_glt_fabc_Z8JK91D8M7QTBS806A6T?_encoding=UTF8&psc=1

Fast forward and at least for me figuring out what feeds and speeds to use with this little machine has been the hardest. The spindle does go to 10k but I can’t get anywhere near the feeds you typically read about online with people using machines that have 4 and 5 figure price tags.

Good luck!!

Btw, I haven’t had any luck with that style of but you posted. They seem to sand more than they cut and generate a ton of heat (will easily remelt plastic if that’s what you’re cutting) and they dull fast. Find something with flutes - one or two and no more than 3.