I just got a recurve that is #45 @ 28" and I was wondering if anyone could help me with choosing the right size of aluminum arrow and broadhead weight combo any info is greatly appreciated

Well we are going to need more info.
1) how close or far from center is the shelf cut?
2) what is your actual draw length?  Longer than 28 add # shorter than 28 minus #'s

Just based on the bow specs I would have to  guess,  2016's with probably 145-175 grain up front as a guess/ suggestion.

Others will chime in as well

Easton has an arrow chart to determine choices based on draw length & bow weight. Look at their website. You'll need peak weight which is your draw weight at full draw plus whether your bow is center shot or not.

If your draw lenth is close to 28" you should be able to shoot Alum 1916's with 100-125 gr points out of your 45 lb recurve.  2016's should work if left full length but you may have to shoot heavier heads.

my draw is 28" exactly and I'm 95% positive the bow is cut on center

Also just wondering what does broadhead weight do to effect arrow flight I'm very knew to this

Good questions newbe. BH weight shouldn't noticeably effect arrow flight other than arc maybe because of heavier weight. Although sometimes BH's plane. Spin test & adjust has always fixed planing for me. Trad prefers penetration over speed; therefore, FOC, EFOC, etc are goals of some to increase this complete passthrough likelihood.

2114's and a 125 gr head would probably tune as well.

Oxtail, adding more weight in the point makes the arrow act weaker in spine (the amount of deflection, bend, when a 2 lb weight is hung on the arrow center with the shaft supported at two point 26" apart for wood, 28" for carbon).

lightening the point or shortening the arrow make it act stiffer in spine. Less center cut will make the arrow act stiffer as well. I often with very heavy tips have to use a thicker side plate or build it out to tune the arrow.