The best spell (there is no other, regardless of what other says) is to build your own self confidence, learn to trust and love yourself, without transform into an Egoist.
There are courses for this, but also if you attend groups of people regular, you can work with yourself to move borders.
Start by so simple trick, to say to yourself that you shall smile to at lest 3 new people each day, and at least have a conversation with a new neighbor each day.
Tell yourself each day when you look in a mirror that you can manage this, NEVER say to yourself that you can't, or that you are dumb, or that none care for you.
The more you use the negative statement, the more your brain will make you insecure, the more you use positive thoughts, and actions, the more will you succeed in improving yourself.
Our Brain is our strongest tool, and we need to have a focused learning process, if we by any chance has a low self esteem.
Remember that we are all different, that none value alike, some can adore a cactus, other can just see the barren and sticky plant, the same goes for humans, we love so different, and from different views.
So put up goals for yourself, always give yourself kudos, never talk negative about yourself, smile a lot, and you will improve with good margin....you are your own BOSS
Good luck