How to get the outbound and inbound capacity of a node using LND? I expected to find an option on lncli to get the exact inbound and outbound capacity of my node, but this is not the case. What is the best way to have this information?
lncli listchannels will tell you the local balance and remote balance of each channel (in satoshis). 

You could simply sum up the the balances of all your channels to find the total outgoing capacity (local balance) and incoming capacity (remote balance) you have. Here is a one-liner that reports the sum of your inbound capacity (requires jq):

lncli listchannels | jq -r '.channels[].remote_balance' | awk '{sum+=$1} END {print sum}'

lncli channelbalancewill give you the total outgoing capacity you have, but until AMP is commonplace, it may be more useful to know the capacity of your largest channel alone.