You will no doubt get better answers here than I am able to give, but I'll share what little I know, plus our experience.
I am guessing you met online and he visited you in UAE in 2021 and you got married. However, I find that bit of guesswork difficult to reconcile with your statement "we have been apart for over 3 years now." In fact, that statement does not really square with "Our relationship started in 2020...". How can you fairly be said to have been apart for 3 years when you had no relationship prior to 2020? Although, if the relationship started in January 2020, given that January 2023 is just around the corner, then you are closing in on 3 years. Maybe that explains some. But, if that's there case, and if really apart for nigh on 3 years, your June 2021 marriage must have been online, which will preclude spousal sponsorship.
But leaving aside my nit-picking over what I see as certain non sequiturs in the story so far (just ask
@armoured about my penchant for nit-pickery

) let's turn to your questions.
(1) Help with documents. Not sure anyone can offer much there. These are not really documents cases. If you have spent any time reading on this forum about what's needed for a successful TRV application, you know you will want to show past travel to countries such as US, UK, Aust., NZ, etc. Then show strong ties to your home country, such as a good job to which to return, home ownership, family depending on your presence, etc. Also show decent bank balance and that the money in the bank came from a regular, reliable source (eg., salary). The only documents of importance are ones proving those items. But, you maybe have your ducks in a row under those heads, since the denial letter you received says nothing about any concern pointing to lack of funds, travel history etc. The underpinning of the refusal might lie elsewhere, addressed below.
(1a) Your first question is really 2 questions (nit-picking again, sorry).
The second part of your first question asks if is it wise to receive AOR before applying for TRV. Again, if you have done much reading here, you will have read that once an outland spousal application is in the works, the chances of TRV approval go down. The IRCC will assume you are coming to stay and to apply inland. But, the most common view I have seen is that, if you decide to apply, you will have a moderately better chance if you wait to get AOR first.
(2) Here, you ask “Should we state that I want to come into the country to visit my husband for our wedding anniversary which is in June? Or should we state that I want to be re united with my husband for the complete 6 month period and then return to my family in UAE?”
That suggests to me that you intend to ask for a TRV for 6 months. Again, stock advice here will be that asking for that much time will be fatal to your application. If really a tourist, you should be asking for more like 3-4 weeks, not months.
Your wording also suggests to me that you may have already weakened any new application by having failed the first time, if indeed you asked for 6 months on that occasion. I am guessing that might be the case, given the reasons given in your refusal letter. You were told, in effect, that you were not seen as a legitimate tourist applicant. The VO referred to “details” you provided which detracted from the strength of your application. It was maybe seen you wanted to be here to be with husband. The problem with a fresh application now, I would think, would be that you would now be viewed as seeking to back peddle and, in effect, take back some of what you revealed first time around. An effort to rehabilitate a doomed application.
I should confess here that I am among the least qualified here to speak to this matter. Although, if you want advice on how to mount a bound-to-fail application, then yes, I can offer much. I met my (now) wife in the Philippines in 2019. Applied for a TRV for her early 2020, just before Covid. Denied almost the day it went in. Super speedy processing. I guess it was so devoid of merit it was not even necessary to open the file to issue the deny letter. I returned to the Phils as soon as it re-opened in Feb/22 after being closed for 2 years. Applied from here (Phils) in March, before we were married here in April. Denied in July.
We put in our spousal application last month. Part of it involved getting UAE police certificate (among others) for my wife, since she worked in UAE for 3 years (2009-2012). She had no UAE ID and could not apply online. The process of going through the UAE Embassy in Manila was hopeless. So, we travelled from Philippines to UAE last month to get the damn PCC so we could finally put in her PR application. We were there for a week and probably spent CAD5,000 for the trip, but we accomplished the mission.
Will we be foolhardy enough to apply for a TRV again, with her application pending? Maybe. We probably would not do it without AOR in hand. But, I'll bet the IRCC has our denial letter all ready to go. And, given 2 failed attempts, I expect they do all they can to deny her PR application. I am expecting it to take maybe 3 years, with a 50/50 chance of ultimate success. I am sure they'll start by not looking at the file for another year or so, then finding some minor flaw, allowing them to return it, requiring us to start over. So yes, we expect years of wrangling.
As an aside, I am surprised Canada requires UAE citizens (maybe you are not) to apply for TRV. My recent trip was my first (and hopefully my last) there. Everyone appeared to have no shortage of money. I would not expect Canada to ask rich people to apply for TRV.