Well... At first I'd say that depends on how and with whom you live and who is cooking the most meals. Try to communicate your wish and find a compromise. Most people that I know love eating meat and are proud to do so. If you're just responsible for yourself it's rather easy, you check some recipes and more often or not find a vegetarian one that sounds appealing and doable, do it, find a similar one, tweak a couple of things and so on.

That's the way it was for me at least. More and more vegetarian recipes caught my interest and although I'm living like a vegetarian I could say I'm not really trying to be one, it just 'happened' because I adjusted my preferences step by step.

That's also important: you have to listen to yourself - do you want to be vegetarian because you might feel better, most expert opinions say it's better, because of animal cruelty, money ... or because you truly feel this way? It's hard to change and even harder when the underlying cause isn't as strong as we had hoped for; you're only going to disappoint yourself.

Since you're 19 cooking alone is hard enough. Don't compare to Instagram recipes. There are... Dozens of better sources than that. Don't know where you're from but look up the most used cooking apps, all those people can't be wrong. Do you feel like some potatoes would make you feel better? Look up something simple, make it and feel the satisfaction - or not. Trial and error. A lot.

Best - tastiest and cheapest - vegetables are sold by smaller vendors.