Surfing Waves

So, I've been taking surf lessons for two weeks now on a 7'0 board. But now summer is over and they're closed for the winter. On my last class. the crew at my surf school advised me to get a smaller and more maneuverable board. I am 17yrs old, 78kg 178cm. I was thinking on a 6'2 to 6'4 shortboard with at least 45L. Should I be aiming for something like this, or should I stick with longer thicker boards?
Cheers!

1) Do the waves get bigger and cleaner in shape during the winter ?

2) Forget about Volume / Liters. Length is your friend when learning the basics. If you weren't doing cutbacks frontside AND BACKSIDE, then you're not ready to go any smaller than 7'0". Was the 7'0" a softboard ?

1) I don't know about shape, but definitely bigger.

2) My friends who've been surfing for some years now, told me the exact opposite, volume is super important for stability. No I was not doing cutbacks yet, started to work on them but didn't got a single clean one. The 7'0 was not a softboard.

3) Also I have to consider my limited budget of 320€ and I'm looking at used boards.

Thank you for your reply! Cheers!

Neto1024 wrote: My friends who've been surfing for some years now, told me the exact opposite,

Your friends, who you surf with, know you and the way you surf way more than any of us on the forum. You should just listen to their advice, since they know best.

Why don't you ask one of your friends if you can buy one of their old 45L boards they're not using anymore ?

Thanks for your help! I might just do that then.
Cheers! And let this be the beginning of a great journey!