A little background to set the stage and answer some questions. After the Treaty of Passarowitz in 1718 there was a reform movement that felt, that although it was not true that the empire was ignorant of European developments, there was as casual disregard for critical new scientific and technological developments, which was causing the military to fall behind in a modern trained officer corps and an effective command and control system.
The Patrona Halil revolt was in 1730 and was not against reform, but rather what it perceived as the dissolute elite - who unfortunately were the patrons of reform, so their removal caused the effort to dissipate, not to be taken up again until 1774.
Commanders along the Hapsburg front were generally aware of modern developments and applied them to their units, but there was no mechanism for transmitting knowledge to the center, which was run by career bureaucrats. As a result, when too many of the experienced cadres were lost, as in the Second Siege of Vienna, knowledge was lost with them.
As for the size of the army, it's difficult to say - it would really vary quite a bit.
In the 1768 war, the main Ottoman army was 75,000 men, about a third cavalry, with the Crimeans present in similar number, but mostly cavalry.
The Ottomans would have to rely on the Balkans and Anatolia for their manpower - the rest of the empire would be useless for this, any any attempt to mobilize any manpower would result in revolts.
This is a particularly low point for the Ottoman military - it's been at peace for a while, without any real reform of the military occurring. I wouldn't put them up against anyone with much chance of success. In alliance with a modern power they could get something done.
It wouldn't be until the middle of the 19th c that the Ottoman army would become a formidable fighting force again.