hi An interesting thread this...

There is lots of good advice above , most of which I would agree with.

You need to experiment with chords and keys to enable you to both play and sing comfortably.

As is said above, to some extent it depends upon what type of music you wish to sing and play as to what keys you choose and what chords and inversions you use.

As Will and others above said you should try in the main keys to play different inversions at various positions on the guitar to get a more interesting and varied backing.

If you want to play jazz (modern jazz) you will need to be able to master a wide number of chords, part chords, inversions and riffs and to be able to play in virtually any key - and generally not use a capo. Though I have played with an occasion player who has used one.

The main thing is to be comfortable with what you do and the main thing is to enjoy it.

Someone once said (???) "The guitar is the easiest instrument to play badly and one of the most difficult to play well".

Where you fit in is mainly up to you.

Go for it..

Cheers

MikeL2