Geohorn is spot-on about working on slopes, your tractor - your pucker factor - your decision. This is something you'll develop as you get more and more time in the seat. Just the fact that you're thinking about it now instead of after something happens is a good thing.
Below is a picture of MY TRACTOR on a 25 degree slope. I've been going up and down this in 4WD for as long as I've had the BX, no problem. Would I do it going side to side - no way. Where I'm standing taking the picture from the slope is about 15 degrees which I've done side to side, but still makes me nervous so I go up and down. I have nothing but the MMM on, any FEL or rear attachment changes the whole equation.
Be aware if you are going side-to-side, even on very moderately sloped hills turning can flip you without notice especially turning up-hill. More so if you have the front loaded, I've come closer than I like to admit. You've been at it all day, it's getting late and you want to get done, that's when it happens.
Post pictures when you get it all hooked up, we're cheering for you!