Its a lot easier to set up a gazebo with two people, but it can be done by one.
Check the types of pegs and guy ropes that you have, if they are basic pegs, or even more substantial pegs I'd recommend upgrading to drill pegs and ribbed stakes.
I prefer paracord to the guy ropes normally supplied.
Look for drill pegs / rock pegs like these:
www.amazon.co.uk/gp/product/B07SWHTSRR/ref=ox_sc_act_title_3?smid=ATK8G06TG8KA7&psc=1&tag=mumsnetforu03-21
(Make sure that they have the hexagonal head, and you will also need a cordless screwdriver to use them. A cordless drill could do the job, but a dedicated screwdriver will be better at the job)
Double check the holes in the feet of your gazebo legs to make sure the holes are big enough to take the drill pegs
Stakes like these will secure gazebos in most environments.
www.amazon.co.uk/gp/product/B07P1B6BTT/ref=ppx_yo_dt_b_search_asin_title?th=1&tag=mumsnetforu03-21&ie=UTF8
(You will need a lump hammer to hammer them in)
Order more pegs and stakes then you would need to secure the gazebo, it helps to have a spare stake for leverage if they are hard to get out and its better to have spares then to lose one and not have enough. Stakes should come out by twisting back & forth as you pull, if they are stuck solid then use a spare as a lever to loosen them)
If you are setting up alone, then gently separate the gazebo legs a little at a time, walking around to diagonally opposite legs.
Optionally as you make some progress hammer in a couple of stakes, and loosely wrap guy ropes to them. This is to minimise risk of a gust of wind. The guy ropes need to be loose enough to allow you to continue to spread and raise the gazebo, but short enough to stop it flipping. If you have stakes as linked above then wrap the guy rope around a few times without fully tying down. This allows you to adjust easily while continuing to assemble.
As you pass each leg lift it up and put it down, trying to let the gazebo naturally spread without too much tension on the frame.
If possible, when you are able to, go under the centre of the gazebo and push up the central pole. Attempt to push it as far as you can to lock open all the corners.
If you can't raise from the centre then raise the top by raising one corner at a time.
If you have two people then raise two legs at a time, lifting one side only.
Raise one click at a time so the gazebo slightly tips, then raise the opposite side.
If raising by yourself, then put one leg up one click, go round to the next, go up one click, go to the third ... etc
As you're doing so remember to lift and put down each leg allowing any tension in the frame to release.
Note: Gazebos usually have 3 height settings, avoid the highest setting unless you need the height. Generally use the middle setting.
Once you have the gazebo up, adjust the temporary guy ropes.
Add the sides, and adjust the legs making sure the sides all go together without being too tight or too loose.
Use the drill pegs to secure each leg.
Add your weights. Ideally they are either the H style or this style:
www.amazon.co.uk/Crocodile-Trading-Weighted-Shelters-Extra-Diameters/dp/B01C1VXCUA/ref=sr_1_20?dchild=1&keywords=gazebo+weight&tag=mumsnetforu03-21&qid=1602442430&sr=8-20
Finally adjust / secure your guy ropes.
If there is space then put them out at angles, and the stakes at 45 degrees. (Add bunting etc to make them more visible and prettier then just rope)
If there isn't space then put the guy ropes down at an angle along the side.
When you are packing down:
Take a final walk around the gazebo, release any straps and make sure there is no stock, pegs, hangers etc on the frame.
Remove the sides
Lower the legs (The guy ropes will loosen, but leave them attached for the moment)
Unpop the roof corners
Unscrew the drill pegs at each foot
Begin to walk each leg into the centre, then go to the opposite leg etc
Release the guy ropes from their stakes
Don't roll up the guy ropes, flip them over into the roof.
(This way the guy ropes are ready to be secured when you next assemble. It isn't helpful to be uncoiling neat guy ropes while your gazebo is being buffered by wind)
When you have the gazebo dismantled hug it to close it down as tightly as possible.
If the gazebo is not behaving at packing down then stop and reassess. Never force it to pack, as something will get bent.
If there are two of you, then one should fetch the bag and the other should hug and slightly lift the gazebo. The one with the bag places the bag neatly at the feet.
If the bag won't shut properly then the gazebos feet either aren't properly placed in the bottom of the bag, or isn't closed enough.
If you are bagging the gazebo on your own, then it can be possible to bag it stood up, but I find it easier to lay down the gazebo, lay the bag over the gazebo (zip face down), roll them together then finish packing and zip it up.
In principle the instructions often tell you to take the roof off the gazebo and pack it seperately. But that means another job when setting up.
If you do. remove the roof and neatly pack the roof and sides, then hang them up at home etc then you can prolong their life. But especially noting from your photos that you have a white gazebo you are more likely to decide you need a new full set before the roof and sides give up.
(We mainly use cream gazebos, and thought they were pretty clean until buying a third gazebo and seeing the difference, so bought another replacement set of sides & roof)
Have a final walk around, pick up all pegs, stakes & tools.