Google is your friend here because there are tons of free plans to use for just about anything. Just make sure you makes those plans your own by redrawing them on graph paper. That helps me "see" and remember the details and also figure out if I want to make changes.
Theres so much information on the web it can be very easy to become just a virtual woodworker - always planning, watching your tube videos but rarely doing. Go at your own pace but when you try something (and fail) the learnings are really helpful and make a lot of the terminology start to make sense.
What's the setback? I used very cheap 2x4's from Home Depot and was a bit careless in my selection. If you look closely at the picture you can see the right side of the bench is level with the floor but the Upper left corner lifts off about 1/2 inch from the floor. The wood I used for the stretchers (the 93 inch long pieces) weren't perfectly straight and I was both too lazy to plane out the boards (straighten them) and just didn't notice. As Lasergunpacker pointed out in a comment to the previous post, the wood you purchase at big box home improvement store really isn't top quality and you need to take your time in selecting the wood. I'll do a post on wood sourcing and selection but it looks like I need to do some more research!
To repeat myself, woodworking is essentially a series of mistake corrections and I think the weight of the bench top and saw will force the frame to be square. If that doesn't work I'll need to add some more braces and there will be some swearing, lots of swearing - the magical incantations of woodworking.