Try keeping it very simple as Jesus and the disciples did. His commandments are not confined to the synoptic gospels, but continue on as promised by Jesus in John 16:12-13 (KJV)
12 I have yet many things to say unto you, but ye cannot bear them now.
13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.
Jesus' preaching continued into Acts 1 taking the gospel message beyond the "4 gospels". He again speaks in Revelation. So counting the continued ministry of the Holy Spirit throughout the inspired 27 texts we find many commandments attributed to Jesus.
I take the following verse to be a primary commandment promise.
John 14:21 (KJV)
21 He that hath my commandments, and keepeth them, he it is that loveth me: and he that loveth me shall be loved of my Father, and I will love him, and will manifest myself to him.
As for any new commandments, here's an example from one apostle.
2 John 1:5-6 (KJV)
5 And now I beseech thee, lady, not as though I wrote a new commandment unto thee, but that which we had from the beginning, that we love one another.
6 And this is love, that we walk after his commandments. This is the commandment, That, as ye have heard from the beginning, ye should walk in it.
That is the greatest of all the new commandments.
It is simply getting out of the house, perhaps going to a store to shop, deciding beforehand you will express genuine love for someone, even a person breaking into the checkout line. This is a great time of year to be the first in line to pay a remaining balance at the counter. I was behind a young mother whose WIC and SNAP wouldn't pay for some snacks, so she began piling up enough to clear about $3 worth. I stopped that with a $20 bill, the change to be kept by her, and said "Merry Christmas, Jesus loves you and your sweet children, and so do I".
That quietened quite a number of people, slowed the line, but the checker was more than OK with it. My blessing was seeing the joy on the young woman, the checker, and others who were blessed. I always carry extra cash for that purpose, saying with my mouth "I will bless someone today as You arrange it, Lord". That was a small obedience to love someone combined with giving to the poor with joy, the sort of action that got God's attention to Cornelius, who also prayed a lot. It isn't the money but the intention in one's heart.
Be someone's "Cornelius" (Acts 10:1-2) in your day to day activities while always ready to preach the gospel. Add to such actions one more commandment in the New Testament. There are about 800 categories of commandments in those 27 texts to choose from. Read your Bible daily with one of your goals to find a commandment that sticks out. Put the one into action by declaring your intent to perform that. Oh, Lord, I want to do that." He will answer that prayer. If the Lord leads you to the very situation to perform it, you are blessed. If the Lord knows you intended, but there was no opportunity, He blesses anyway. He will put that one 'on lay-away'. Add another the next day. Memorize another one the next day and do it immediately, at least really desiring to, open to opportunity, day by day a little at a time. That grows into multiple discoveries, committments, and the opportunities daily sometimes, opening up chances to introduce Jesus to folks who don't hear much gospel. God is also sending you to other "Cornelius" folks who need Jesus along with their good works. And remember it is love to bless the stingy, too, for they need to meet real Christians possibly for the first time.
Blessed Christmas to you.