My go-to recommendations for first packers are, in no particular order:
MASHO
3.5" Mr. Limpy
4.5" Reelmagic basic in SOFT
4" Sailor
The MASHO is nice because of the 3D balls and that it naturally hangs down, however I personally felt the balls were too small. It was good though because it was a forgiving packer- ie if I placed it wrong, it didn't really get the boner effect and I never had to worry about it. Was my first and was perfect.
The 3.5" Mr Limpy is soft and reasonably durable for the cost, as well as CHEAP. I recommend packing it to the side in tighter underwear, because it can stick out or look a little pointy in loose underwear. It's still my go-to when I want a less obtrusive packer.
The Basic RM in soft is my absolute favourite but is a little pricier. I LOVE my 5" but thing it's too much for a beginner packer. I also have a 4.5" which is reasonably sized as well, and I've heard the smaller ones are great too. Again, in the SOFT style, classic can be a bit hard.
And the 4" Sailor I recommend for people who think the MASHO or Limpy is the right price but too small and they don't want the next size up. The next size up of Limpy is huge, it's actually the hardest to pack out of all of my 8 packers in my opinion. Around as difficult to pack with as my pack-n-play 5" from freetom and about the size of my 5.5" peecock. and Masho unfortunately only comes in one size. The Sailor is a nice 4" packer. The detailing is it's biggest flaw.
3.5-4" is where I feel is most affirming while also being easy to pack. Once you get into the 5" range, it becomes more to deal with, and it's completely doable if you want it, but I think it's better to start small and learn with a more forgiving size. Natural flaccid for cis men is I believe like 3.6" or something, so the 3.5-4 range is most accurate to the cis. If you're interested in phalloplasty one day, the 5" is where most people end up packing because phallos don't get bigger for sex and have a higher average length than a cis flaccid penis.