Best way to find out is to sketch it out to scale on graph paper. Then you can see how much clearance you have between pieces.

Thanks, I just did the drawing on graph paper--If I fit the bed under wood beams (shorter side of room) there's 18in on each side of bed (taking in consideration the bed frame, baseboard and bed linens) --Is 18in. enough space on each side to walk around bed. There is more space if I move the bed to longest side (11'10") but is not under the wood beams which is the dominant focal point. What do you recommend?

IMO, seeing the bed face you as you walk into the room is the best position. However, there are many cases where that's not the best for space planning purposes. 18" is tight. Too little clearance in most spaces (living room, etc.), but may be ok in a bedroom, where you're just getting in and out of bed. However, if someone with balance problems or an elderly person is in that room, I wouldn't recommend it.

Thanks, so if I change the bed frame to a platform there would be 21in on both sides with the baseboard. Should I change the bed to a queen size or let grandpa take the risk of bumping onto the wall and hopefully bouncing back on the bed, lol?

As much as I love the king I have to admit the queen would fit better in the space.

I think the queen would be a better fit, also.

If this bed is for one person to sleep, the queen size will fit more comfortably. Squeezing between the wall and bed is not fun….

If it is only for one person, then go with queen and shift it over to one side just a bit, to give the person using it a bit more space to get in/out of bed. Leave just enough space on the other side to be able to make the bed. Ergonomics/comfort should be more important than symmetry, for a bedroom.

https://www.urbansales.co.nz/loft-japandi-platform-bed-frame-super-king

This bed looks like a possibility. You can purchase the side tables separately. I'll leave it you to figure out the measurements.