Changing theme without losing current changes

I want to try changing my theme, but I don’t necessarily want to commit to a new one if it doesn’t work out for me. Since I am new to all of this, I do a lot of guess work and I struggle when it comes to editing themes and such. This is why I’d rather not lose the changes that I’ve made to my current theme. So, to make a long story short, can I save my changes if I change themes? Thanks!