I am vegan (coming up to 2 years). I recommend transitioning by replacing dairy / egg products with alternatives slowly. For example, find a vegan chocolate you like instead of normal chocolate, try all the plant-based milks to find one you like (I originally only tried soya and rice milk which put me off, then I discovered oat milk which I love). You can live a very healthy lifestyle on a vegan diet, but make sure you get enough of certain vitamins - particularly B12. If you drink fortified plant milks or eat soya yogurts (check the back as some aren't fortified, such as the organic ones) then this shouldn't be a problem. I've never needed to rely on supplements.
Supermarkets are great for free from stuff but make sure you read the labels as some stuff is free from dairy but not egg, and sometimes the free from stuff is not even vegetarian. There are lots of freezer veggie burgers and sausages that are also vegan, also a few quorn products are vegan (clearly labelled with a big vegan sign). I recommend joining some of the vegan facebook groups as they're great for advice and finding out about products.
Also, vegan ice cream is the best!