I am low on space. Inspectin my store with
sudo find / -xdev -type f -size +100M -exec ls -la --block-size=M {} \; | sort -nk 5
gave me 20 most heavy files
-rw-r--r-- 1 pi pi 102M Dez 18 11:58 /opt/pycharm-community-2020.3.1/lib/platform-impl.jar
-rw-r--r-- 1 root root 116M Nov 16 19:05 /var/cache/apt/archives/scratch3_1.0.6_armhf.deb
-rw-r--r-- 1 root root 121M Jul 10 2020 /opt/Wolfram/WolframEngine/12.1/SystemFiles/Java/Linux-ARM/lib/modules
-rw-r--r-- 1 root root 121M Nov 28 18:42 /usr/lib/jvm/java-11-openjdk-armhf/jmods/java.base.jmod
-rw-r--r-- 1 root root 121M Nov 28 18:42 /usr/lib/jvm/java-11-openjdk-armhf/lib/modules
-rw-r--r-- 1 pi pi 136M Nov 10 16:37 /home/pi/.sdkman/candidates/java/11.0.9.hs-adpt/lib/modules
-rwxr-xr-x 1 root root 137M Aug 3 03:06 /opt/Wolfram/WolframEngine/12.1/SystemFiles/Links/GeometryTools/LibraryResources/Linux-ARM/libGeometryTools.so
-rwxr-xr-x 1 root root 138M Nov 18 21:15 /usr/lib/chromium-browser/chromium-browser-v7
-rwxr-xr-x 1 root root 139M Nov 18 21:15 /usr/lib/chromium-browser/chromium-browser
-rw-r--r-- 1 pi pi 143M Dez 16 15:26 /opt/pycharm-community-2020.3.1/jbr/lib/libcef.so
-rw-r--r-- 1 root root 176M Dez 6 05:09 /var/cache/apt/archives/openjdk-11-jdk-headless_11.0.9.1+1-1~deb10u2_armhf.deb
-rw-r--r-- 1 pi pi 191M Dez 21 21:24 /home/pi/.sdkman/archives/java-11.0.9.hs-adpt.zip
-rw-r----- 1 root adm 266M Jan 16 20:02 /var/log/syslog
-rw-r----- 1 root adm 300M Jan 16 20:02 /var/log/daemon.log
-rw-r--r-- 1 root root 587M Sep 3 19:21 /var/cache/apt/archives/wolfram-engine_12.1.1+2020081901_armhf.deb
Wolfram Engine is the most heavy. I dont use it and dont know what it is. Is it safe to delete it?
sudo apt purge wolfram*; sudo apt autoremove
will get rid of it. It also means you installed the wrong version of RaspiOS. The full version includes it. The desktop version doesn't.