Here's some of the UK NHS's advice on feeding babies, with the non-vegan bits edited out.
Your baby's first foods can include mashed or soft cooked fruit and
vegetables like parsnip, potato, yam, sweet potato, carrot, apple or
pear, all cooled before eating. Soft fruits like peach or melon, or
baby rice or baby cereal mixed with your baby's usual milk are also
[Cut food into p]ieces about the size of your own finger.
Try grabbable bits of soft, ripe banana or avocado.
Once your baby is used to the foods above, they can have soft cooked
pasta, noodles, toast, pieces of chapatti, lentils and rice.
To replace those non-vegan bits, focus on giving fat- and protein-rich foods like avocado, pulses, and well-cooked and cooled beans.
Foods that are common allergens like nuts, seeds, soya, celery and mustard should only be introduced one at a time and in very small quanties to reduce the risk of baby developing an allergy (the same applies at any age; there is no benefit to waiting until they are older to introduce these foods). Nuts and seeds should be ground into a paste or butter. These help to provide nutrients that would otherwise come from meat, eggs and dairy, so it is a good idea to try to introduce them.
Avoid any foods with added sugar or high in salt.
Keep breast feeding while introducing food, if possible. Vegan infant formula is a tricky topic and soya, oat and almond milk, (which may be introduced as drinks from 12 months) can't replace it. Breast milk would be the only source of B12, for example, until baby is old enough to start eating fortified foods or suitable supplements. You should consult a doctor if you can't breast-feed.