I think you are being misled by the CI volume calculator which, frankly, gives ridiculous results. For example, there is a junior
pro surfer called Kai Hing who is 150lb - so only just heavier than you - and surfs 24L boards. Why anyone would suggest you should be on a lower volume board is bizarre.
Secondly, if you plus your stats into the Firewire Surfboards volume calculator (on the firewire website), or this CI one
http://vol-app.com/ChannelIslands/ you end up with a result of 40 - 50L, which is a much more sensible result. For a start, keep in mind that you are a beginner - you might think you can surf, but an intermediate surfer is someone who has done perhaps 5 years of surfing 3 days per week. That isnt you, no matter how naturally skilled you are. Secondly, your fitness level might be excellent but you arent surfing fit (because you havent been surfing). Finally, you havent surfed for a year. It might not be as easy as your memories make it. So you are a beginner.
So look for a board of at least 40L. forget the 23L board, i dont know anyone who surfs a board that small who is older than 13. And even if you are 13, you havent been surfing for 5 years like they have. Indeed, 40L is the minimum.
Secondly, volume is a highly debated issue in surfing but there is one thing everyone can agree on: you do not start your board choices with volume. Volume is used as a 'check sum' ie having selected a board that is of the size, width, outline, rocker etc that you think is suitable for your skills, the waves and so forth, then you check the volume of the board you have chosen as a final matter to ensure you have made the right choices earlier on.
for example, each of the following boards has the same volume, about 32 L. But they range from 5ft3 to 6ft10 - clearly totally different boards for totally different purposes. Volume tells you nothing about which board is suitable for any particular need

- 5ft3 32.4l.png (97.65 KiB) Viewed 1566 times

- 6ft10 32L.png (31.1 KiB) Viewed 1566 times

- 5ft7 32l.png (65.25 KiB) Viewed 1566 times
So what you need is something wide (21inches+) and fat (2 5/8+) and at least 6ft6 (to be honest, probably closer to 7ft) and preferably with flat rocker. Look at some the JS boards (eg blak box) or the firewire boards (dominator) or other egg or hybrid/fish type boards. Then having found a board like that, check the volume and make sure its at least 40L or more. I dont necessarily suggest those boards I named are the ones to buy (indeed, they are both boards more suited for an intermediate), but they are the type of boards you should be looking at, not some 5ft nothing potato chip.
If you wanted my honest opinion, I would recommend you get get a 7ft mini mal. You will have much more fun much quicker. You will catch more waves. you will learn much faster - you cant learn unless you can catch waves.You can learn to trim and turn on a mal.
I appreciate that you dont have the money to buy multiple boards, but almost every beginner says this and my answer is
1. if you get into surfing big time, you will find the money if and when you need it. You just will. And if you dont get into surfing big time, but just recreationally, then getting a bigger board that lets you be unfit and out of practice and still able to surf on is a much much better choice than some high performance board you will never be able to surf properly.
2. it is extremely unlikely that you will get to a skill level that exceeds what the board can do within 5 years ie you can surf the board you buy for 5 years. that is not to say you wont want another board, or feel some limitations (eg if you are surfing 9ft longboards), but it will take you a long long time to be more skillful than your board can handle
3. as you get better, you will be able to surf smaller boards. But you cant jump straight to the board you might be able to surf in 5 years. Think of it like, say, maths at school. After 5 years of high school maths you will be able to do calculus (or whatever!). But if someone puts a calculus question in front of you in grade 7 and doesnt teach you anything else, will you ever learn to do calculus? Probably not, because you dont know the stuff that lets you understand calculus at all.
Finally, if you are still growing then you can probably expect to put on a bit more weight over the next few years - so a board that seems 'big' now wont be big by then.