Show first n lines of a file, e.g. /var/log/ufw.log:

sudo head -n 5 /var/log/ufw.log

Output:

Oct 15 00:00:24 vmd36600 kernel: [19324490.078347] [UFW BLOCK] IN=eth0 OUT= MAC=00:50:56:3e:2b:ae:28:99:3a:4d:30:af:08:00 SRC=59.96.109.87 DST=207.180.232.52 LEN=40 TOS=0x00 PREC=0x00 TTL=53 ID=1287 PROTO=TCP SPT=15848 DPT=23 WINDOW=17823 RES=0x00 SYN URGP=0
Oct 15 00:00:41 vmd36600 kernel: [19324507.267767] [UFW BLOCK] IN=eth0 OUT= MAC=00:50:56:3e:2b:ae:28:99:3a:4d:23:91:08:00 SRC=103.102.231.2 DST=207.180.232.52 LEN=40 TOS=0x00 PREC=0x00 TTL=248 ID=54321 PROTO=TCP SPT=32943 DPT=8728 WINDOW=65535 RES=0x00 SYN URGP=0
Oct 15 00:01:04 vmd36600 kernel: [19324529.840642] [UFW BLOCK] IN=eth0 OUT= MAC=00:50:56:3e:2b:ae:28:99:3a:4d:30:af:08:00 SRC=77.90.185.160 DST=207.180.232.52 LEN=40 TOS=0x00 PREC=0x00 TTL=247 ID=54321 PROTO=TCP SPT=46497 DPT=18701 WINDOW=65535 RES=0x00 SYN URGP=0
Oct 15 00:01:24 vmd36600 kernel: [19324549.948246] [UFW BLOCK] IN=eth0 OUT= MAC=00:50:56:3e:2b:ae:28:99:3a:4d:23:91:08:00 SRC=104.250.34.154 DST=207.180.232.52 LEN=40 TOS=0x00 PREC=0x00 TTL=244 ID=19184 PROTO=TCP SPT=40875 DPT=3389 WINDOW=1024 RES=0x00 SYN URGP=0
Oct 15 00:01:46 vmd36600 kernel: [19324571.791459] [UFW BLOCK] IN=eth0 OUT= MAC=00:50:56:3e:2b:ae:28:99:3a:4d:30:af:08:00 SRC=64.20.30.187 DST=207.180.232.52 LEN=40 TOS=0x00 PREC=0x00 TTL=246 ID=26202 PROTO=TCP SPT=47595 DPT=5900 WINDOW=1024 RES=0x00 SYN URGP=0