I want to make a stand so i can hang my heavy bag outside in my backyard.
I'm completely new to wood working however, so i would really appreciate if someone could guide me into the right direction.

My questions are:

1. What type of wooden beams should i buy? How thick should they be?
2. Should the top beam be as thick as the ones on the side standing straight up?
3. How deep should the wooden beams go into the ground to make sure they stay up?
4. Do i pour concrete at the bottom of the wooden beams? And if so, do i put the wooden beams in a bucket and fill that with concrete or just a hole in the dirt?
5. If it's just a hole in the dirt, i've seen people recommend small stones/pebbles at the bottom of the hole but wouldn't this make it vey difficult for the beam to stand straight/solid?
6. How do i keep the beam standing straight while the concrete dries? So i have to use instant drying concrete for this?
7. I would like to have enoough space to circle the bag, is it possible for the top wooden beam to be around 12 feet? Or would this make the whole thing unstable due to its length?
8. Is there anything else i should focus on to make the design better? I'm currently going for something that looks like this.

1. 2x6 beams would give you a strong support
2. Ideally yes. 2x4 would work aswell but for extra support 2x6 is reccomended
3. A metre would suffice
4. Bucket or hole would suffice
5. Stones or pebbles dont make any difference either way. Not enough of a difference to care about
6. Thats not a worry, once the cement is packed to keep the beam straight you can leave it. Just dont touch the beam until the cement is fully dry
7. 12 feet would be more than sturdy enough
8. Not really. Design is totally up to you. Just keep it simple and folow the basics. It sounds like alot of work but its fairly easy when you get cracking on with it.