Journal entries:

(1) increase in allowance for doubtful accounts 113
ALLOWANCE FOR DOUBTFUL ACCOUNTS 113 (DR)
ACCOUNTS RECEIVABLE 113(CR)

(2) interest accrued on notes receivable 24
Interest receivable 24 (DR)
Interest revenue 24 (CR)

(3) Depreciation on equipment 320
Depreciation expense 320 (DR)
Accumulated depreciation 320(CR)

(4) Expired insurance 126

(5) Store supplies on hand 85
Supplies expense 85(DR)
Supplies 85(CR)

(6) Interest accrued on notes payable 36
Interest expense 36 (DR)
Interest payable 36 (CR)

(7) salaries accrued but not paid 340
Salaries expense 340
Salaries payable 340

(8) Merchandise inventory , dec.31/20XX 7220

Not sure but do u need the inv on jan1/20XX DR 6040??

No. 4 Debit Insurance Expense and Credit Prepaid Insurance.

No. 8 You need to know what is the amount in your Merchandise Inventory account, then subtract your ending inventory amount to get your adjusting entry amount. Your entry will be: Debit Cost Of Goods Solds for the adjusting entry amount and Credit Merchandise Inventory for the same amount.

Your other entries look good.