Gardening

and the canes for next year seem very small and underdeveloped compared to the ones I just harvested this years berries off of. Is it normal that they be so small at this point?

This picture seems to suggest that the primocanes (this year's canes) are going to be smaller than the floricanes (canes that sprouted last year)
This would make sense since the primocanes have only been around for 6 months, while the floricanes for 18 months

You should be comparing the size of the new canes to the size of the canes last year, idk if you're doing that

As Hello_Kitty_enjoyer mentioned, it's not abnormal for these canes to be smaller at this point. You don't mention where you are located but I am assuming you've got a long way to go in the growing season, at least 2-3 months.

I'm sharing some photos of my raspberry bushes at different times to demonstrate. The images are in reverse chronological order. Currently, I've got new shoots coming up everywhere. It's wild. It can take a few years for them to become established so don't worry too much the first year they are in the ground.

Photo dump

Some varieties fruit on the primocane too, but it sounds like you know that they don't. Do you happen to know the variety you have? This will help you better understand what to expect. New growth comes from different places on different varieties. I grow two varieties that behave very differently and it's a little confusing to see them side by side to be honest!

If they are in the ground they will need less feeding than in a pot. When in a pot they are in an artificial environment and can't source the nutrients they need. I don't really have to feed my raspberries at all, but I might throw some alfalfa meal (nitrogen, to support green growth) or compost (grab bag!) at the base in the spring.

You shouldn't fertilize too close to the end of the season because you will be encouraging growth that might not get time to get hearty to the cold and will be damaged.

Good luck and have fun!

Supposed to start feeding when it warms up. You can start feeding them with liquid nutrients asap and get some growth before summer ends. I would use something synthetic if you want quickest results, nonorganic liquid is also beneficial here bc you can be sure that it'll get in fast and get used up quickly so you can stop feeding towards the tail end of summer where I think you want to let it hunker down.

5-5-5 or 10-10-10 fert may be fine. You may have better luck with something geared towards tomatoes at this point, since you're looking to grow fruiting bodies? If you want to stay organic I'd stay away from fish emulsion tho, too much nitrogen, unless you mix it with other organic solubles

I can't actually help you, but can I ask some questions about your plant?

What year did you have the bush put in?