I live in Belgium, how can I make my life cheaper?

Hello everyone

I just found out we were practically doing frugal living without knowing this was a thing. Mostly because we are broke. But I am wondering what you all actually do that is considered a lifestyle of this. Hopefully more specific to people living in Belgium (aka tax and cost hell)

Firstly, with the gas and electricity prices going up and food being a disaster for buying cheaply, I was wondering if I could have some insight directly from you all into adapting a more cost friendly way of growing our own food.

I've scrolled through some pages, articles, etc. But can't hurt to ask here again!

Living in Belgium we are prone to very different weather types (sometimes even in one day) and a lot of cold and rain. I know nothing of gardening, nor do I have experience with it. So I was wondering what foods we could realistically grow well in this climate, I found some information but I was more curious on how sustainable most veggies, fruits, herbs, are to grow in this sort of climate throughout a year for a working family?
For people living in the same or a similar country I also ask if overall you save money making your own foods like mayonnaise, bread, etc. compared to the stores here?

How else do most of you optimise your wallet to your life? We often use blankets and candles for light and warmth and often try to travel with public transport instead of driving a car, but I feel like there is more we can actually do that we don't realise yet?

Sorry if its been asked before, but there is just a lot of activity in this subreddit and I feel like its easier just outright asking you all what things you do.

Thanks!