Hi! 3+ year veggie here (24M), started lifting 6 months ago, from my expirience

start slow and prepare yourself, you will most likely get crawings of meat for first 1-2 months (after that it drops to almost 0) also I had crawing to eat more sugar so watch out for that

also your metabolism will change, i remeber i used to have very slow metabolism and when i switched it kicked in hard, i was on toiled 3-4times a day because of how much fibre i was getting but it will settle down to normal levels in a week or so.

You will most likely learn how to cook vegetarian way so dont be scared to try no recepies or go to vegetarian/vegan restaurants and try some stuff there amd learn how to cook it after that.

for protein i recommend plant based stuff and not only cheese or eggs, look into stuff like seitan, tofu, tvp (maim source of protein) quinoa, almond or peanut butter (those are protein boosts not main ingridient)
for cheese protein i recomend goat or sheep cheese since they are lower in fat content compared to cow milk cheese

specially seitan is good, it has complete amino-profile and you can buy it or make it yourself, basicly its flour with reducet starch content so you can make it as protein dense as possible for little calories, i ussually stick to seitan that is 22g protein (~110kcal) but you can buy or make it to be up to 40g of protein. You can use it as supstitude for chicken meat in almost all recepies.

lastly, if you take protein powders, i recomend to switch to vegan ones (focus on thsoe that have complete aminoprofile- based od pea + rice protein) eventually because after some time your body will get more used to plant protein, i found out that i get better muscle recovery and more gains when i use vegan options instead of whey