There's no two ways about it - film photography is an expensive hobby. I calculated that every time I press the shutter button on my Rolleiflex, it costs me about £2, considering film, development and scanning costs. You are going to have to bite the bullet to some extent. But I think film photography is a fun and rewarding hobby - it's worth keeping that in mind too.

(By the way, digital photography is an expensive hobby too - think how much film you can buy for the price of a Sony α7R IV!)

I would suggest avoiding expired film. Film is one of the most important factors in how your images turn out. Why would you want to risk introducing problems into your image making? Buy fresh film - you won't have to worry about how your film was stored or how it might be expected to perform, and you will be supporting the film industry and continued film manufacture.

By the way, I don't think it's correct to say that colour rendition can be quite variable depending on the lab. Developing film consistently, for an established lab, is not a difficult process. I would say that experimenting with expired film is going to be a much bigger variable in the colour rendition of your images.

As regards particular films, I would say just experiment! Well, as far as your budget allows. You won't really know what you like until you try it for yourself. I usually stick to the big two - Kodak or Fujifilm - but there are lots of options. Read the description from the manfacturer to see what kind of characteristics a film has - saturation, contrast, etc.

Also, if you use Instagram, I enjoy following images with a certain hashtag. If you're interested in some particular film, follow that hashtag on Instagram to see what kind of images others are making. It's great for inspiration too.