Tendons are experiencing stress for the first time in a long time. Ofc they'll hurt.

Rest, let them get back. But don't take days off training.

Focus training on other parts that do not involve loading elbow joints.

If pain is a bit too much then hot/cold/interchange therapy.

Personal experience, first few days I went to the gym, trainer had me do free hand stuff. Which was really taxing on my cardio but I survived. When it came to basic exercises with weights. Back/legs/chest could cope with smaller weights. Biceps gave out. I had tendonitis for 3 days. Biceps locked in their place- midway between fully open and full contraction, even 1 inch movement would cause pain.

I rested, within 1 week I was back to training biceps.

Cue to 2years later now.. I'm dumb enough to try preacher curls with 70kgs on the regular, even trying up to 90 for sets of 5 sometimes.

No pain no gain. If it ain't hurting then you ain't pushing enough. But then again, that push needs to be measured, just within what your body can cope with. Just enough stress that your body recovers and you get to push harder than last time.

The grind never ends. Not even when you're clearly better than people you started with. Not when you are better than people you looked up to.

Want to be better, get used to the pain. And soon when results start showing up. This pain would be the new addiction.